Download Single and Three Phase Overhead Transformer

Overhead Distribution
Transformers
5-833 k. Single Phase
30-500 kVA Three Phase
2
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All
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POWER
PARTNERSiNG
Ropresentod by and
Nareplated for ASS Inc.
Il 1! 1!
F" ".'i
About Power Partners, Inc.
Power Partners, Inc. manufactures poletvpe
distribution transfor'mcr., that provide more
than 3,000 utilities in North America, Central
America, the Middle East and Asia with electric
power for homes and businesses. Power
Partners' poletype clistrihution transformers
are specifically designed to serve residential
overhead distribution loads. The y arc also suitable for light commercial loads, industrial
lighting, and diversified power applications.
Power Partners provides a complete line of
overhead transformers to meet the applications of any distribution system. The company
manufactures single-phase and three-phase
polettipe transformers at 34.5 kV and belo
in ratings from 5-833 kVA single-phase and
30-500 kVA three-phase. The Power Partners
core-coil design provides optimum efficiency
and excellent mechanical, thermal and electrical performance.
The Power Partners operation in Athens, GA,
has achieved ISO 9001: 2000 certification. The
operation, which was an ABB facility until
Power Partners purchased it in May 2003. has
nearly 5 y ears r.)r manufacturing experience.
The ABB Connection
The polctvpc disti'ibuhon transformers manufactured by Power Partners are name-plated
for ABB, with ABB serving as the manufacturer's representative for Power Partners. ABB
is a global leader in power and automation
technologies that enable utility : and in(IListryr
customers to improve their performance,
while lowering their environmental impact.
Manufacturing Technology
Overhead distribution transformers manufaactur'cd by Power Partners offer cost-effective
solutions for power clistrib u i on. The latest
manuFacturing technology is utilizedi to maintain state-of-the-art quality and productivity.
Large vertical integration allows us to ship
high quality : products in the shortest possible
production cycle.
d
POWER PARTNERS
The Value of Quality
Power Partners is committed to achieving total
customer satisfaction and industry : leadership
through continuous process improvement.
The company's employees are team-based and
measurement focused, and their work is based
on highly disciplined processes. The company
is innovative, reliable and driven to provide
high quaIityr and high Value, and to meet each
delivery commitment. \ want Power Partners
to be recognized as a company that exceeds
customers expectations.
An Industry Leader
N orking together with ABB as the mantifacIurer's representative for Power Partners, we
have alliances with major utilities and businesses around the worst[ providing products
and services to meet all their needs. Together,
we are a dominant force in the industry.
Single Phase Overhead
Distribution Transformers
I'c nVc1- I'artn cl'S single p11a sC.
oil-filled.
1][11 0-1111 1L11)ted dis-
tributinn transformers are specifically designed for ser v icing residential overhead distlilWti[ in loads. .111 e y are also
sU itablc for light commercial lc ds, inc]Lltitrial lighting and
divcrsificd power applications. These transformers arc
designed for the application conditions normall y cncountcrcd on electric Lltilit power distribution systems.
l aser CtCIICc] :111[ 1di/ed a 1L111111111111 na incplatc \+ith bar
coded serial number.
14. The paint finish process applies a C]L11aable, corrosion
resistant finish t the prod Let. The finish meets or
exceeds all the performance rec]L11rcnlcnts of ANSI
C57.12.29. )he nuLllti- ti tep process includes an epoxy
13.
p ri mer unifiIrnlly applied he cationic clectro- deposition
and a Urethane top coat.
The following additional featLlre. y
self protected type CS P " U nits;
15. P ri mary protective link.
16.
are
all standard on
Surge arrester.
17. Secondar y Circuit breaker.
18. Secondary breaker operating handle ith e m e rg e ncy
overload reset and overload signal light.
n
tv
Type CSP"
Sr
It.)
4
`5
Ratings
Type S
• 5-833 kVA
• 65 C tcnlpcl'aitL11Y rise
• 60 hertz standard, 50 hertz optional
• Low voltages: 120/240, 240/480 and 277
• I Iigh voitagcs: 2400 th1-0 gh. 34,400 Volts
RQ
• In ulaticm lccls:
Options
480-600
1.2
:0)
2160-2400
5.0
60
4160-4800
8.7
15.0
7;
7200-12470
1
r o nal / 5 k 1 1OI. 12000 e
1. 3200-14400
19920-22900
95
1I. ai u dabic
18.0
25.0
125
150
ritvr i,n/ /25 ' V lilt. 199`'0 e n1l.+ae unable
-34400
34.5
200
Standard Features;
]Legs.
2. Arrester mounting pacts.
3. Cover-mounted high voltage porcelain bushings)
with eyebolt ternlina] (10-100 kVA) or spade terminal.
4. Low voltage insUllators are available in fiberglass rcinforccd polyester material or porcelain (both eyebolt
and spade terminals),
1. lifting
5. Low voltage neLJtral glY1L1nding strap (fU1rnished On
10-50 k\'A single HV hushing Unit s }.
6. ANSI support lugs (hanger brackets).
7. Cover has 13 mils minimum of polyester coating providing 15 kV dielectric insulation of tank ground parts
from li ve parts and increased resistance to corrosion.
8. Self venting and resealing cover assembly
9. The core/coil bolt-in pads are 180 apart.
10. Embossed low voltage leads.
11. Oil filled IllLJg\^ith cover ground strap.
12. 'lank g1YaLlnd pad.
I'rinl arv Termination
• Cover-nloLmtcc] high voltag e porcelain bushing(s)'k+itl-I
spin top terminal.
• Side-wall mounted high voltage porcelain bUShing(5)
with spin top terminal (Standard on all 4800 Volts an(]
below ) .
• Primar y current li miting backUp fLlyc.
Secondar y Termination
• I. ow Voltage porcelain Bushings ith NEMA spade terminals (Standard on all units 167 kVA and above).
Primary Switching
• Externally-operated tap changer.
• Externall y-operated dual voltage switch or internal
terminal board.
OVC'CL11'1'Cnt I'1'I )tC41 on
• Intcrnalh- mounted current limiting fuse in ,cries with
protective lint .
Contact the division for voltages and dimensions on 666
thn ugh 8-i kV'\.
Optional Accessories
1.. 1-ligh voltage bushings
are
of two types and are mad e
of wet 1)rocess porcelain;
• Speed wrench operable c}°clxolt bushing for cover
mounting.
• Spin-top bushings for either cover or side-wall
n1oLlnt.
!. '1^ip changers compensate for small voltage variations
along the dlistl - 117L1tion system. 'hue externall y
tap changer is a single-phase,
design for dc-energized operation.
five - position
-operatd
POWER PARTNERS
A dual oltagc itch permits use of the same transformcr on distribution s ystems with different sv°stcm
• The MOV polvnncr arresters hL i ndI SL1rgcs of
65,000 ampctrs (small block) and 100,000
amperes (large block).
• Secondary C1rCL11t brea kers protect against over-
voltages.
The CSP protection package consists of four related
components that work together to provide complete
self contained protection against surge
.
CL11 1C.nts. short CirCL11ts and ov erloads:
• The protective link removes an internally-f a L1lt cd
transformer from the primary line, maintaining
-
l oad s and external sho1 t CirCL11ts.
• An optional C LJ rrcnt li miting fLJSC supp]Cmcnts the
protective link when the f[L Lilt CLJ1 . 1 - Cnt cxcceds the
li nk's rating.
Stainless steel tanks and covers arc availLihlc.
Serv ice to C thC1 • CLJSton1C1 • S On the
e line not serv ed
b y the faulted Unit.
Overhead Distr ibution Transformers
Approximate, +hr, ght5 and dime.. n5iony
APPROXIMATE WEIGHTS AND DIMENSIONS
OVERHEAD DISTRIBUTION TRANSFORMERS
Standard Design 1 ]imcnsions and 'eights
(All wcights and diiiicnsions are approximat e . Dimensions may change to meet
the customer spec.)
Single Phase, 60 HZ, 01SC, 65 Hiss High
Voltage
(Refer to Division for available tap
positions and dimensions for other
primary voltages.)
Low Voltage 120240 or 2401480 or 277
Standard Performance level
g.
A
E
q
N
E
^ ^in
C
B
75-100 KVA
IIIII
IIIII
- 0
Liiu
q
a
^^®
®
1 67
500 KVA
q
C
B
1.5-50 KVA
Overall weights and dimensions arc given in pounds, inches or gallons and arc approximatcs
A = Ove ll F-Height. 13 = O v crill Width, C; = Overall t)cpth, 1) = Tank Diameter. F. = Hanger Spacing
I Phase
34
I
' '
H
36
20
22
I:,. '=
13. ' 5
] 2
375
5[l
41
44
U
P
H
22
,,,
24
,.+
11.25
11.25
2U5
236
41
11
2 +-
12
349
3
1S;
17.5
1. 7.5
1. 1.25
11.25
11.."_'>
489
>S 5
510
6U5
29
3]
i0
75
49
25
27
20
23.25
850
875
1 00
50
27
28
20
2325
923
968
167
'50
333
58
66
62
38
38
42
33
33
37
24
24
_'+
23.25
24
24
1475
1820
2040
1542
1885
2110
78
90
82
^r00
66
1^
+1
_-
36
2850
2950
11)9
FF
10
3
1 .5
117
22
22
25
'is
20
24
24
27
1. 3.2
13.25
1. 7.5
17.5
20
1 1 ._°5
11.25
11.25
11.25
11.25
!i>>
245
.
?I25 0
37.5
50
38
46
46
51
505
730
526
755
II
II
29
28
41
38
75
52
25
28
20
23.25
910
936
IOU
56
2-
_)s
20
23.25
98 5
10215
+6
167
'S0
333
56
68
l
38
38
42
33
33
35
24
24
24
23.25
24
24
1430
1969
1970
1495
1930
2041
70
Q1
-5
2960
3U
141
4
27
36
39
111 -Approximate Dimensions shown reference designs with +j- 2.5% 'laps
POWER PARTNERS
A
Transformer Protection Package
for Overhead Distribution Transformers
-
,
I
ticr I'artncr5 c ffcrS f( )U I I) LbSiC ti iThfo1 111C1 tv'pcs: S, SI':
>
CI and CS1"`. 'Together they represent a wide ningc of
prutcctivc capabilities to meet ncarl every application.
Fo r transfornlC.rs suppliCC] \pith OVCrCL11TC.ilt protCCtIon,
the user must assure coordination with system protcc-
tive devices. F ailure
to do so will defeat the PLJ1T)05C of
such protection.
ti\c link opcl'atcs, taking; the load c)ff tll • tl-;1n^fi 1Inc_IhCforc the corc/coil is damaged.
Current-Protecting "CP" Transformers with Current
Limiting Fuse
This t pc tl'ansformer has the Same characteristics as
type "CF plus the ability to ]inhit fault cUJn-cnt to the
tran s for m cr.
the
®
Self-Protected "CSP " Transformers
I
The CSI coCorclinatcd protcctic)n package is available as
an option on Power I' wrtncrs overhead distribution trans-
-}
Type S
forrnCrs for increased protection against 5LJrgC CL1rrCnts,
shol't circuits, a nd overloads.
tZ
LQ
Type CSP"
S
Conventional "S " Transformers
Phis t pc ti n fo^rmc1 , cc:ntain5 no protection CCiuipmcnt.
Therefore. lightning, fault and overload protection for
thes c transfc l'mcrs must he provided by purrllascrin^tallccl. L3utiiliLir\ pre tccti c dciccS.
Conventional "5" with Protective Link
The protcctivc link is the ] cast cxpcnsivc device nioLinted
in the transformer to protect the system if ni a dcfcctive
transformer. 1k11cnever tlicre is an intc,-nL11 t'LllIU1 the
resulting fault current Wi]] cause the protective link to
blow. isolating the transformer fr in the priniwwry feeder.
Surge-Protecting "5P" Transformers
1'hc 'SF transformers inclLLlc t1 nSfo I-11101'-111CoLinted
lightning arresters and intc 1 'nall y -n1o LJ nta] high voltage
protective ]inks, but omit the internally-mounted low
volt age circuit brea ker, 'E1lcsc tra nsforniei's arc used in
loc ations w111Y li ghtning is a problem. However, bccaLJ c
the protective ]ink protects the system only from outages
d Lie to internal transformer fail L re, overload protccti on, if
cl ircd. mutit Inc Ilrcnidccl I c,tcrmal iLJSOS.
Current-Protecting "CP" Transformers
v
The "CI' transformers are equipped with the intcrnallv
kc1- and high voltage -nioutC1lwvagercLtI)1Y.
protectiv e links, but omi[ the lightning arresters. Thcse
transformers are Llscd in locations whet t lightning is not
SL11
C I)1Y.)tCCt10n 1S desired.
1. I'n tcctivc I.inL
a) Hcnlo v cs an internally-faUlltcC] transfbrnier from
the primary line.
b) Operates at to 14 tinics normal full load current.
a)
Both the current liliiiting fuse and the plutcctiv e link arc
fuses working togcthcr to give full range transforl,lrr
protection against f ault-Current. I'lIC 1)rotCCtivc li no intcry
l'LO ptS an low f alUllt cL11'1'Cnt While the current limiting
fuse protects ag ainst fault currents which exceed th e
interrupting rating of the protective link.
S
Features
2. Second ar
Conventional "S" with Current-Limiting Fuse
and Protective Link
a problem. The arrester ma y he crossarm-mc anted if
1
y
P r otects
Circuit Breaker
against overloads and external short
c1FCLlits.
b) Coordinated itll protectiv e link, trips on an
external short or overload before the link blows,
and only if th e overload is large or continUous.
c) If overload is small or temporary a load managcnlcnt light signals the need for change-out to a
lal ;cr unit for more optiniiicd tlansforrncr' loading.
3. MOV Pol v nlc1 • Arrester
Provides protection fi • onl lightning and switching
S Ll rj?C S.
4. Optional partial-range current 1in1itin fuse (in series
with protectiv e link)
a) Limits the n1aximun1 current in the circuit.
b) Reduces current to zero in less than one-half
cvc] c.
c) Minimizes th e possihility of eventful f3i11.11' ,
The CSP` protection package is available on Sinlc phase
and three. phase ov cnc e ad distribution transformers in
the following ratings:
• ;inlc I'llase, LV 120..240, 10-100 kVA
• Single Phase, LV 240/480, 10-167 kVA
• I'llrec Phase, 30-150 kVA
'rhe breaker and protective link arc coordinate(] Such
y
-
that an f l[ It Or short Cil ULJit on the seCondlar1 sid c of
the transformer will trip the breaker before the protcc-
POWER PARTNERS
Class Designations
1. I'> pcC:al' . alx>c5 W. ]0-100kVA.
e
Class A: Two tull -i nsulated high voltage bushings, two
arresters, two protective links and extcrna] breaker han-
dle. Suitable for app]icatic in on either wyc or delta distriIxition systems. Single-position pole mounting in
accordance with latest ANSI standards.
Class B- 1:'TWo Tulle- insulated high voltage bushings,
one arrester, two protective links and external breaker
handle. Nornla]]v applied on solidly grounded systems.
Class B-2: One full - insulated high voltage hushing, cinc
arrester, one protective link and external breaker handle
Suitable only for application on solidly grounded distribLition sv v stenls. Single-position pole nioLinting in accordance with latest ANSI standards.
Class B-3: Same as class B-2 except with two-position
mounting.
2. Type CSF' , 5 kV and below, 10-100 kVA. Similar to
Type CSP' above 5 KV except:
• Sidewall-mounted primary bushings.
• Class B-2 and B-3 not available.
y
1. 'Cypc 5, above 5 kV. 10-500 kVA.
Class A: Two full - insulated Iiigh voltage bLishings, sLut-
able for application on either wye or delta distribution
systems. Single-position pole nloUnting in accordance
with the latest ANSI standards.
Class B -2: One full - insulated high voltage hushing, suitable only for application on Solidly goaLlndCd d istril7LltiOn
systems. Single-position pole nic:unting
in accordance +ith the latest ANSI standards.
Class B-3: Same as class B-2 except with two-position
niOUnting.
2. Type 5, 5 kV and below, 10-500 kVA. Similar to Type 5,
above 5 k\ except:
Siddewa11-n10L1ntedl primar bushings.
Only Class A is available.
•
y
F
1
CLASS DESIGNATIONS
TYPE CSP HV ABOVE 5 KV 10-irxl KVA
75-100 KVA
ANSITYPE'B' LUG
75-100 KVA
[ANSITYPE'B'LLl
•
(
a
+-
E' =E .. 5i
Imo'
CLASS A
CLASS B -2
<V {
I
TYPE 'B LUG
CLASS DESIGNATIONS
TYPE S. HV ABOVE 5 KV. 70-501; KVA
75-100 KVA
/ANSITYPE'B' LUG
CLASS A> IC KVA
POWER PARTNER
ii:
CLASS A C,n KVA
•
CLASS B -2 <
•
CC
KVA
CLASS B-:r x: 75 KVA
Center-Bolt Cover Design
[ I1 C CXCILISiVC CCI)tCl'-I)OIt C[ AiCI C]CSI.n is titanclall.] c:n all
Power Partners overhead transformers, 5-500 kVA single
phase and 30-500 kVA three phase. The cover asscnibly is
unique in 1)Oth operation and design. ['11C unlit offers an
extraordinary high withstand capability and an extra margin of safety.
'
Standard Compliance
A. Pressure Venting and Resealing
The self-venting cover design meets the pressurC venting
and resealing myuil emcnts of ANSI C57.12.20-1997, paragraph 6.2.5.2.
"A cover assembly designed fir relief of excessive pressure
shall remain effectivel scaled for overloads and external
secondary short circuits of the magnitude and duration
allowed by industr standards and loading guides, but
shall relieve pressure at a minimum of S lbf/in', gage (55.2
kPa) if designee] to reseal; or at a minimum of 20 lhf/in',
gage (138 kPa) if designed for pressure relief without
resealing. Such OpCRitiiin shall occur before other conlponcnts of the tank are ruptLiI'C] or displaced, and the cover
shall remain in position. Manual means of venting the tank
before removal of cover shall be provided.
No auxiliar pre sUlre relief device is required on Power
Partners overhead distribution transformers. The flow
rate of the center-bolt cover after venting is significantly
higher than that of auxiliary pressure relief devices
resulting in increased safety and higher tank withstand
capability
•
y
y
y
Advantages
y
is pressLJ1-C relief provided by L1nlgLle
• Static and d namic
venting and resealing capability.
• Increased safety provided through higher tank withstand capabilit and auto Matic pressUrC venting c]ulirig
cover removal.
• No aLlxlliar pressure relief device is required.
• Extra insulation provided by thick epoxy coating.
• Increased resistance to corrosion provided by sloped
cover and thick coating.
• Increased resistance to ]eaks and breathing provided
by unique gaskcting system.
• Simplified maintenance provided by single cover bolt.
y
y
y
Features
I. Center-bolt cover, cover beam and beam support lug
system provide:
a) Self- venting and resealing which meets ANSI specifications eliminating the need for an auxiliary
pressure relief device.
b) 'link withstand capability in excess of the rcgluirenlCnts of NEMA TR1.
2. Increased tank withstand capabilit and automatic
lllr.ssurc relief during cover removal result in
increased safety.
3. Electrostaticall -applied epoxy coating is a minimum
of 13 mils, providing an average of 15 kV dielectric
strength to provide extra insulation and protection
fi-onl corrosion.
4. The 15' slope of cover prevents moisture from collecting and increases resistance to corrosion and
]caking.
5. Continuous hollow nitriIe gasket, raised and flat
bushing cmbossments, undercut gasket scats on
bushings, and copper-encased cover bolt gasket provide increased resistance to leaks and breathing.
6. Center cover bolt provides easy cover removal compared to chime ling design, resulting in lower maintenance cost.
y
y
B. Tank withstand
The Power Partners overhead tank and cover design provide tank withstand capability far in excess of the 1 v ciui renients of NEMA TR1-2000. Part 2, Page 6, Section Dr
"'rest No. I — An Arcing Fault in an Enclosure"
"l. First Fault. A sin)Lllatcd internal fault slla]I he provided. This fault shall consist of a 1-inch ale gap
mi.iunted horizontally and located 1 inch above the core
clamps. This gap shall he bridge(] initi,3lly by a 0.060sinch diameter or smaller copper wire. [lie gap shall Inc
connected between the high-voltage terminals or from
one high-voltage terminal to ground. The mounting
blocks or terminals of the gap shall cc insist of copperbearing material and shall have flat surfaces from 112 to
3/4 inch in diameter or in „idth. 'These gaps shall he
designee] to maintain this 1-inch are gap for the duration
of the fault. The transformer coil shall not be electrically
connected in this test circuit. TIC power Source shall be
7.2 kV and adiuStCC] to supply a current of 8000 rms symmetrical amperes."
•
POWER PARTNERS
As this arcing fault wi]] not be self-clearing, hack-up protection shall be provided to clear the circuit in approximatcly 112 to 1 cycle which is a typical clearing time for
an cxtc1'na] clistrllhLJtion fuse CL1toLit. A CL1toLJt \\1th up to
2. Second Fault. For the sccc and fault, the fault
dcscrihcc] in item 1 shall he rcpcatccl.
This overhead tank and covcr system can withstand a
20,000 Ampere one-inch arc on the specified test.
a 25K fuse link Shull he used to provide hack-Lip 1p1'c.)tCCtion. A currant-limiting device, such as a fuse, cannot be
includes] in the back-up protection."
:ES
eoa
700
400
300
200
COQ
10
20
30
zcr.^lT^r.^n:i Y^sdrn
POWER PARTNERS
W
Low Voltage
Spark Gap
An internal 1(n+ +oltage spark };ap has been dc+cic )hed aO
a means of protection for distribution transformers
against secondare side. surges. The Electric Utility
Indutitrr has been eoncerncd about transformer failures
attrihUted to secondar y surges, a]though the f(;11L11 - C rate
is estimated to be ]css than P5% per year. The entilr
sLlbject is Very complex. bU t the phenomenon is very
much related to system parameters, such as, house and
pole groU nd resistance, length and type of service drrip,
and transformer load. - I'he sU rgc impedance of the transformer coil is also a significant flctor. resulting in units
larger than 50 kVA being t y pically imrnLinC from this type
of failU re. The Power Partners spark gap will provide
the same degrees of protection as any other method
presently avai]ablc, and at a significantly lower cost.
Apphoation
The spark gap is mounted internally between the low
voltage line hushing and the low voltage nCLltral and is
designed to arc oVC1- (]Li ling low Voltage sakes to protect
the transformer +in(Iings.
Testing
I',.ti li',1Listive testing has proven that (1) the internal spark
g i p operates under surge conditions to protect the
transformer winding, (2) the arc is extinguished Under
high acailahle fhLJlt current conditions, and (3) the Operation of the internal spark gap, under maxim urn oil temperature conditions, and,+ith a wide range of oil vapor
to air ratios, does not result in the development of an
unsafe condition. This extensive testing proves conclusively that the internal spark gap provides the same
degree of protection as that provided by interlaced
secondary windings, low voltage MOV arresters, and
external spark gaps.
Advantage
1.',ffccti+c — prevents low-side surge failures.
Cost effective — a spark gap is considerably lower in cost
than the other suggested methods of prevention.
Reliable — a spark gap does not degrade the overall transformer Or the s y stem reliability
Easy installation — the internal spark gap can he easily
retrofitted onto existing transformers.
The spark gap mounted internally on the LV neutral bushirra
with the electrodes connected to the X1 and X3 bushings.
10
POWER PARTNERS
JUMBO "Step Down"
Overhead Distribution Transformer
"J LUI4'1fkJ I)1 St l'i1]Lltic 1I
1i 1111Sto1111C I'} a1'C C Icsi8nc(1 as
single phase, two-winding transformers—specifically
for "Step-Down" applications.
T
R
Y
^
0l. Pin )totvpe testing 1nsL11'Cti tIIC , ]L1111I7o design Call meet
1TIC]L15trV short CircLlit standards and prov ide reliable
service.
7. Self-venting and resealing cover eliminates the need
for an auxiliary pressure relief device and offers
increased safety- through higher tank withstand.
8. ANSI suppc. 1 1-t lugs (hanger brackets) are rod-welded
to the tank wall for added strength.
9. Anodized alL1nlinLln1 laser inscribed nameplate oilers
1
5L3L)
Standard Features
y
1! ii
1. Lo-Hi-Lo cc it design divides the short cil'CLllt force
between two low-high spaces increasing the short
circuit strength of the. coil.
2. 'Roo winding construction yields a much higher
i mpedance than 15 characteristic of a n auto transformcr which helps limit the mechanical forces the.
Unit 01 List Sustain dUring faLllt CdL1tV.
Progressively wound coils with adhesive
resins on
thermally upgraded insulating paper provide
increased short circuit and thermal strength.
4. Sheet con(]Llctor in IV windings enables the electrical
centers in the high and low to align thcrrselv'cs n1inimizing the vertic al component of short cul - CU1t fortes.
5. Rcinfiirced core-coil assembly provides greater sho r t
cin uit ithstand capability.
3.
POWER PARTNERS
longer term readability
10. Lifting lugs are positioned directl y opposite the
cover beam Support lugs, reCdU sing the chance of the
tank going out of round when lifted.
11. Cover mounted high voltage porcelain bushings with
cvcuolt terminals are m[1Llntcd on flat embossments
on th e cover and have Undercut gasket scats for
improved scaling. 'Pie eyebolt connectors are cast
bronze plated with tin,
12. Low voltage porcelain bushings with clamp-type t e rminals provide case in making secondar y terminations.
13. Arrester r e. unting pads are resistance welded to the
tank wall. completely and unifi rmh filling the surfaces where p ad and tank wall join, to pride
greater strength.
14. The p aint finish process applies a CILJ1 - a blc , corrosion
resistant finish to the product. 'f'hc finish meets or
exceeds all the perfon'mance rCL-JLJ cmcnts of ANSI
C57.12.28. The multi-step process includes an epoxy
y
primer uniforml applied by cationic cicctrodcposition and a Urethane top coat.
Ratings
• 50-500 kVA
• 65°C Rise
• 60 Hertz standard. 50 Herb optional
• I ligh voltages: 7200, 14400 and 19920
• Low voltagcs: 2400, 4800, 7200, 7620, 7970
Standard Design Dimensions and Weights
JUMBO LIQUID IMMERSED OVERHEAD DISTRIBUTION TRANSFORMER
TYPE S. HV ABOVE 5 KV, 100 KVA
ANSI TYPE '`B" LUG
ANSI TYPE '`B" LUG
'A
Q
I
I
m
®
m
m
I
I
A
I
I
I
I
I
I
I
I
I
I
I
I
LV > 600 VOLTS
5000 VOLTS
LV 5000 VOLTS
A]] Approximatc 1.)imcnsions shown rcfcrcncc dcsigns with -/-2.5% Taps
umhv
t
H
-5
Not A vai]ablc
100
167
+5
58
t;
24
28
25
!U
75U
785
52
52
31
33
31
37
31
33
22
27
1095
2010
1150
2090
41
37
33
'-
23 • +U
1.i.i[l
88
85
45
45
37
39
33
36
27
27
2400
3Ub>
2500
,1(»
120
5[1
333
5[1U
5i
(9
64
:
88
Ovcntll , eights and i ncnsions are givcn in potmdti. inchcs or gallons and are approximates
A = Overall 1-lcight. I3 = Overall Width. C = Ovci^ill 1)cpth, L) = 'link 1)i amctcr
12
POWER PARTNERS
Three Phase Triplex
Overhead Distribution Transformer
die I'cn+cr Partners li'iplcx c.l\cilieacl diStl'11}Llt1[11i tCansformer can be Used to serve three phase applications
through 225 kVA. 'Triplex designs consist of three scparatc single-phase core-coil assemblies in one. tank.
No
11
Q
1
-
45
EA
Triplex overhead distribU tion transformers are often used
to serve large motor loads Hhere the motors are fi • egL1Cntl1' started. Oil field 1]Llnlping loads and sonic irrigation pLlnlping loads shoL1lrl use onl y triplex designs. Also,
the 1hplcx transformer has international applications
here 1)v 9 and Dv 11 phase displacement are rer]L111'cd.
Ratings
• 30-225 k\A
• 65 > C rise
• 60 Hertz standard, 50 Hertz optional
• High Voltages: 13800 and below
• Low Voltages: 208Y,120, 240 x 480, and 480Y,277
• 'Transformer Bll., Ratings
Transformer Primary
'Transformer BIL
2400
60 kV
4160
60 kV
7200
75 kV
8320
75 kV
12000
95 kV
12470
95 kV
13200
95 kV
13800
95 kV
POWER PARTNERS
Advantages
• liasicr, cleaner installations are provided by thvcc
phase overhead transformers compared ti l thrce
single-phase units.
• Reduced installation costs, lower operating costs,
safer operation, minirniied service disruptions, and
increased tlansfbrincr life. provided by an optional CSP
protection package.
• The capability to serve large motor loads requiring frequent motor starting is provided by triplex designs.
• The same design, nlanL1factLlring and perforniance
advantages that are provided on Power Partners single
phase overhead distlihution t1 ansforn c s are incorporated into the triplex design.
Features
]. \d1L1nC1 core with step-lap joints for increased
efficienc y and lower noise levels.
2. I'rogressiVC]V wOLlnd coils with adhesive resins on
insulating paper or conductors for increased shortcircuit strength, efficiency and thermal strength.
3. CSP protection package available as an option for
increased protection against surge currents. short
circuits and overloads:
• I'limar y protective links
• SUl gC arresters
• Secondar y circuit breaker
• Secondary breaker operating handle with cmcrgency overload reset and overload signal light.
4. Three point core-coil bracing for increased mechanical strength.
5. Self-venting and resealing cover that eliminates the
need for an auxiliary= pressure relief device and offers
increased safet y through higher tank withstand.
6. The paint finish process applies a ciurable. corrosion
resistant finish to the product. The finish meets or
exceeds all the performance requirements of ANSI
C57.12.28. The multi-step process includes an epoxy
primer uniformly applied by cationic cicctrodcposition and a L11tithane top coat.
7. Cover has 13 mils minimum of polyester coating
providing 15 kV dielectric insulation of tank groU nd
parts from live parts and increasing resistance to
corrosion. The cover is sloped 15 preventing water
from collecting, thereby reducing the chances of
corrosion and leaking.
8. 'Tank bottom rim is three lavers thick for increased
cdurability and resistance to shipping and handling
c] am age.
Standard Design Dimensions and Weights (All weights and dimensions are approximate.)
HV > 5000
HV < 5000
Overall weights and dimensions are given in pnun(IS, inches or gallons and are approximates
A = Overall Height. I; = Overall Width, C = [hcrall 1)cpth, 1) = 'fink 1)iamctcr. E = Hanger Spacing
: .
1;
14
tl ic_ dktance
bet ccn the I • Liin er Iwackcts.
POWER PARTNERS
Three Phase "T-connected"
Overhead Distribution Transformer
I'll c I'cn+cr I'L1 rtncrH I'-Omncctcd. c cnccaaC1 Llistl'117L1tii ill
transformer can he used to serve most three phase applications up to 500 kVA. "'1'-connected" transformers consist of two single-phase core/coil assemblies. This tYpc of
connection is also re1c1'red to as a "Scott-T O connection.
" '1-connected", overhead distribution tninstornicr can
be used to serve most three-phase applications.
However,'1'riplex designed three phase transformers are
needed for sonic applications where large motors arc
the lc ac] and these motors are frequently started. Oil
fi eld pumping loads and some irrigation pumping loads
She )ulcl use only the triplex designs.
A
Ratings
• ;;[1-500 kVA
• 65'C rise
• 60 Hertz standard, 50 Hertz optional
• High Voltages: 13800 and below
• Low Voltages: 208'1120, 240T x 480'1; and 480 17277
• 'Transformer 1311. Ratings
li-an storm cr Primary
'li-ansformcr BIL
240U'F
60 kV
4160T
60 kV
4800'1'
60 kV
7200T
75 kV
75 kV
8320T
95 kV
12000'1'
12470'1'
95 kV
95 kV
13200T
13 SOOT
95 kV
Advantages
• Easier, iii ore economical and cleaner installations are
provided by three phase overhead transformers compared to three single-phase units.
• Lighter weight Lind lower cost
Mded by "T-connected"
design compared to conventional three-phase design.
• Elimination of overloads from s y stem unbalance by
operating -- --connected transformers without I)1I'ma1'1'
groLlitcis.
• Avoidance of transformer neLJt1'al 1'CCquircrncnt since
third harmonic currents on "'I'-ccmnected" teinsformcrs are negative s UjUicnCC not 1Y'CgL111'ing a gi - ound path.
• Reduced installation costs, lower operating cost, safer
operation, minimized service disruptions and
increased tlansformc,- life provided by optional CSI'
coordinated protection package.
• The same design, manufacturing and performance
advantages that arc provided on Power Partners single
phase overhead distilliution transformers are incorporated into " •1'-connectcc] -• design.
p1A
POWER PARTNERS
Features
1. We uiid core with step-lap joints for increased effcicncy and lower noise levels.
2. Progressively wound coils ++ith adhesive resins on
insUllating paper or condLJCtorS for Increased shortcircuit strength and thermal strength.
3. - 11irec point core-coil bracing for increased mechanical strength.
4. CS! > protection package available as an option for
increased protection against Surge CL11'1Y.nts, short
circuits and overloads;
• Primary° protective links
• Surge arresters
• Secondar y circuit breakers
• Secondary breaker operating handle with emergency overload reset and overload signal light.
5. Self-venting and resealing cover that eliminates the
need for an auxiliary pressure relief device and offers
increased safety through higher tank withstand.
6. The paint finish process applies a durable, corrosion
resistant finish to the pi - odLiCt. ' Pie finish meets or
exceeds all the performance rcy . i 'cments of ANSI
057.12.29. The nlUllti-step process inclLides an epoxy
y
primer uniforml applied by cationic clectrodcposition and a Urethane top coat.
7. Cover has 13 mils minimum if polyester coating
providing 15 KV dielectric insulation of tank ground
parts from live parts and increasing resistance to
corrosion. The cover is sloped 15 preventing water
from collecting, thereby reducing the chances of
corrosion and leaking,
R. 'Sank bottom rim is three la y ers thick for increased
CILlrability and resistance to shipping and hLin(11ing
damage.
Standard Design Dimensions and Weights (All Weights and dimensions are approximate.)
A
A
HV 5000
HV r 5000
Overall weights and dimensions are given in pounds, inches or ga]]ons and are approximates
A = Overall Hei ,ht. H = Overall Width. C = Overall Depth, 1) ='Kink 1)i;3inetcr. F = Hanger Spacing
3 Phase 7' - T Connected
1:3
._.
26
+5
^':
112.5
1511
225
][3
40
2 1)
4$.4
43 2
57
57
61
64
28
28
30
30
34
22
_21
24
5
47
36
36
36
36
•i5
54
54
29
33
28
28
10
40
1 12.5
1511
62
62
61
33
40
37
30
30
34
22
22
24
69
11
36
27
80
45
42
27
725
;[3[1
500
_.
I._=.
29
33
31
40
37
41
11.2)
2 3.25
43 .25
36
36
99'
] li r. ;
1530
177(1
2215
750
3560
720
1035
1.175
1625
1. 8.40
2303
2860
3650
=,
tt
5'
62
70
81
98
118
.1)1)
.3-
it
905
11-5
965
1225
43
50
1505
1 - 25
1565
1780
2275
59
65
84
36
2285
3
2915
3015
100
3815
3900
123
E is the distance between the hanger brackets.
All Approximate Dimensions shown reference designs with +j-2.5%'hips
16
POWER PARTNERS
Distribution
Transformer Testing
I'Ii s It ver I'titnci'S ('cnnmitmcnt to manuf;dctLll'C C]Liallt
distrilxition transformers is backed by a series of transfornier tests usCC] tot enT Confitrrnancc to performancc
characteristics OL1tlinCC] in the latest ix visions of ANSI
C57.12.00 and ANSI 057.12.90. '171csc identified tests arc
a]so part of the Quality System which is aUldited semi annuall y h 1)h°f N0SKP, VF' RI'1AS (1DNV) to the ISO St andarc]s.
Testing Program
Factory tests are performed on a transformer to confirl,1
that it is properly designed and constructed to carry
rated load and that it will withstand the conditions it viii
be exposed to in service.
Each transformer nun LifactLired by Power Partners n1 List
undergo a series of tests.
I. Polarity, Phase-Relation. and Ratio
2. Applied Voltage Test of the HV
3. Applied Voltage Test of the LV
4. InC]L!CCC] Vo]tagC'lest
5. No-Load (Excitation) Loss and Excitation Current
6. Circuit Breaker Tcst (for CSP transformers only)
7. Impedance Voltage and Load Loss
8. hill \X! e Impulse
9. ContinL11tV wreck
Test Facilities
•
lllc multi-station, automated test facilities are operated
by process control Con1pLltera. ECClL11i'C(] interaction with
test floor personnel is minimal with the ConlpLlters initiating and monitoring each test, and then analyzing the
test rYsL11ts feedback. The computers are programmed to
condUCt tests according to ANSI standards, and according to the ratings of each transformer style, the test floor
computer
initiate appropriate test sctUllls, compare
results with established ANSI standard limits, and determine acceptance for each tested unit.
Will
•
1110 test 1'CSLllts for each Unit are recorded and Stored on
cornpi.ltcr files for acces and analysis.
Polarity, Phase-Relation, and Ratio Tests
•
Ilicse tests verify proper phase-relation (t111Y.e phase),
ratio, and polarit y (single ph as c) of the transformer L1nClCr
test. To pass, unit nUSt demonstrate the proper polaris
or phase-relation and have a tLii-ns ratio within one-half of
one percent if the nominal vi iltage ratio.
L3
Applied Voltage Test of the HV
I I is test checks the dielectric integrity of insulation
stl'LiCtL11Y.s between the high voltage and low Voltage, and
between the high voltage and ground. A pass/fail decision is ma(]c b y nlonitoi ing the test current intensit y. If
the resulting current is larger than specified normal leakage and capacitive currents, the Unit is rejected. This test
is omitted for transformers vOth a llcrnlaincntlygroundcd
high voltage winding.
POWER PARTNERS
Applied Voltage Test of LV
Phis dielectric test is similar to the Applied Voltage test
of the high voltage circuitry except that the integrity of
insU lation structures between the low voltage and the
high voltage, and between the low voltage and ground is
checked. A pass-fail decision is made by monitoring the
test current intensity. If the resulting current is larger
than specified normal leakage and capacitive current,
the Unit is rejected.
Induced Voltage Test
file
I u pose of this test is to verify the dielectric
strength of turn to turn, layer to layer, phase to phase,
and other insulation structures within the transformer
windings b y i nducing an overvoltage condition (at higher
than nctrm:31 frC(]LienCV to avoid saturation of the core).
The test CLJ1'1'C'tlt monitored, and if it exceeds limits
specified for each transformer, the unit is rejected.
15
No-Load Loss and Excitation Current
This test measures the no-loaf] tcxcitation) loss and tl-c
transformer exciting current with rated voltage applied.
If the exciting current and/or the no-load loss exceed the
li mits specified, the transformer is rejected.
Circuit Breaker Test (for C$P transformers only)
Phis test veiifies the 1)n )per c peration of the low
voltage
circuit breaker under fault conditions. The breaker is
require(] to operate within a specified time Under a
sitni.ilatc(] fa3Lllt.
Impedance Voltage and Load Loss
This test measures the load loss and the impedance voltage at rated Current. The load loss and the impedance
voltage 1)1utit be vtitl in specified limits.
Full Wave Impulse
The impulse test is one of several tests designee] to verify
the dielectric strength of the man y insulation structures
,, ithin the distribution transformer against line voltage
surges. It is performed to comply with ANSI standards
and fOr quality assurance. The change in the ANSI standard in 1993 required all manufacturers t0 install fault
detection sensitive enough to detect a single turn short.
Continui ty Check
This test is perti irnied on all transformer' to verify transformer C1rCL11t and component integrit y . This test is performed with an c ihmmeter to verify that the internal
wiring is correct.
The transformer's nameplate is compared to manufacturing information for sty]c, serial number, kVA, HV rating,
LV rating. tap voltages, impedance, con LiCtor materials
and coil 131L rating. The bushings, electrical accessories,
and Fuses are verified.
dl
A. Magnitu dC
Special Tests
Sc I1 tests arc performcd at the option
of
the customer
Sound 'Vesting
ANSI standa1Y1S define the WLluircd SOLInd 1CVCls for
transformer bLlt SOniC CLJStOr11C'S Specif y reduced SoUln(1
]cvcls. The Sound generated by a transformer is affected
by the core geometry, flux density, tank design, and the.
quality of assernbl\ : of all the transformer components
i i t a completed unit. tic )u rid tests arc made with the
unit powered at 100% and 1.10° of rated voltage undclno-load conditions.
Temperature Tests
C losses and coil IIlyses arc the plltllar y sOL11 - CCS Of
heating within the transformer. Our transforrnci's arc
guaranteed to have an average coil inding t(niperaturc
of no more than 65' C rise over ambient air tcrn1cratL11 -C
when operated at rated voltage and ]oad conditions.
'ncc temperature test is performed to dctcrlllinC the
thcrrna] characteristics of tllc transformer and to Vcrifv
that tllc~G= arc within design limits.
Calibration
k t C(JL11p11iCllt is calibrated on a SChC(1111C(1 basis by
trainee] technicians. Calibration rccolYls arc maintained in
accordance with the Quality System procedures. 'These arc
audited SCnl1 annuall y by 17NV in accordance with ISO.
Short Circuit Withstand Capabilities
1 )i tl'117Lltio ll ti i fi rincrS arI LJ hjCCtC(1 to 1 external short
Circuits on the sccondar y side.. SUCK external faults can
develop on the service Zinc, in the house wiring or - in
connected loads due to tnLlnieroUS environnictltal 1 - casons. These faults can he line-to-groU1nd. CIOUNc ]1 nC-tog1YlLlndj 111' line-to-line.
To meet these operating conditions, the American
National Standard 1tlmtitutC (ANSI) has sct standards conccrning short circuit \tithstand capability These standard n 1'CClUil - c that di tr ibL1tion transfori-ners shal] be
designed and Constructed to withstand th mechanical
and thermal Stl - CSSC5 pod Uced by these eternal short
Cil- CL11t5.
I'hc current standards 1l • lating to short circuit strength
arc ANSI C57. 12.00 hich sets the short circuit withstand
requirements for distrilbutlon transformers and ANSI
C7.12.90 which provides procedures for short citruit
testing.
For distribution transformers, the magnitude of the short
cir - cuit Current, th i1L1nlhers of Shot - t-circuit tests and the
duration of each short circuit test are defined bV ANSI
5tandaids its follows.
37.5-100
1.6 -500
112.5-300
500
750-2500
11G1,„
base Current (Symmetrical}
per unit tor- all clistribution tlansf(rmch
with sccondari • rated (50(1 V and belt w.
The shun circuit current will be Iimitecl b y the transfurmelimhec[ancc . nly.
B. Number of'lcsts
Each phase of the transformer shall he subjected to a
total of six tCSts, foul - with s y mmetrical fault currents and
two with asvninlctrlcal faLllt currents.
C. Duration of Short Circuit '[csts
WIIell Sho1 - t C11'CLlit tests are pC 1'f[ 11'n1CC1 tIIC Cl umtion of
each test shall he (1.2 s except that one test satisf ying the
symmetrical current rccluil-cnlcnt shall be made for a
longer (lunation on distrihutii n transformers. The duration of the long test in each cLisc shall he as follows:
Category 1:
T=12501I'
li r e T i the CiUI]'ation in seconds,
And 1=1,I1 R =svrnnlctrica] short circuit current, in 1,1ultiplcs
of normal base cur r ilt CXCCpt I Shall not exceed the maxinlLllll SVn1nletrcal CL11'lcnt nlaf.41lItL1C1C5li tcd in A.
\Vli r-e 1,.=1 h .%=symmetrical short circuit current. in
rills amperes
I k =rated cur - rent on the given tap connection, in rnls
amperes
Z T =tlainsfornlcr impedance on the given tap connection
in pd- Unit on the same apparent power base as 1R
Catcgor-y 11:
T=1.0 second
Criteria of Satisfactor y Pc1-fornlance
According to ANSI Standards a Unit is considered to have
passed the test if it passes a 1 • isUJ l inspection and cliC]Cctric tests. Rcconlnlcndcd adcliti[ )Il;1l checks include
examination of wave shape of terminal voltage and current, leakage impedance nicasurcnlcnt and excitation
current test. (I:cfcr to ANSI 057.12.90.)
The standart allows the following variations in the lcakage impedance:
Z T (Per Units)
0.0299 or less
0.0300 or more
Percentage Variation
22.5-5UU (T)
7.5
Z T =per Unit impedance of the transformcr'
POWER PARTNERS
Paint Finish Process
I'll I'aI'tncrH fact O r •, utili/,c y a paint finish process
called "2CEC' . a ti idcmal'I, for a two-coat cathodic C]Cctrodeprsition i int pre ce55. ' ['1115 new ad anced coating
technique maintains the structural integrity of transfornlcrs that arc subjected to the long-term corrosive cnvironmcnts of coastal areas and 1n(]Lltit1'1al contanlinants.
Paint Process
Cathc dic cicctrodcposition of paint occurs when direct
current is applied to positively charged resin micelles
dispersed in water. The resin micelles migrate toward the
cathode [transformer tank) and are deposited in a proccss known as electrophoresis. As the process continues,
the thickness of the deposit builds, resistance increases,
a n(] the film reaches a thickness limit. The most acccssihlc area,, are coated first, but as the resistance increases.
less accessible areas coat. producing a highly uniform
fil m hU11ld. Two -coat cathodic c]Cctrodeposition is the
application of two coats of paint (epoxy primcl'lacrvlic
L11'('tll',3i1C t[ pcc it).
Iii or to welding to the tank shc]l stamped external hardWare SLJch as Banger brackets and lifting lugs air vih1'atorV f1nishcc] to renmove bLlrrs and inSLJre. a smooth rad1L15
edge to a]]ow consistent edge coating.
An eight-stage dip process provides two cleaning steps to
Conip]CtClV 1'CnioVC ILlhrlcants and soils. A zinc phosphate coating is applied to enhance corrosion prntcction
by providing tighter, more consistent coating than the.
tvpical]V L1 y cd iron phosphate. The use of (]Cionizcd
water in the final rinse stages insures that the surface is
free of salts and ions that caul(] bate]- provide sites for
corrosion initiation. All pretreatment stages arc immcrsion stages, which assLlres complete and total coverage.
The cicctrodcposition process assures complete and
consistent coverage of the entire tank including complex
shapes such as fins, hanger brackets, and lifting lugs.
is "2CEC" proccss allows us to optimiic the performancc of the Ilrimcr and topcoat indepcndentl to maximize corrosion protection and LlltraViolCt li.,ht resistancc
while maintaining superior mechanical properties.
Faint process conSiStCncV is assured through aLltonlated
paint feed and monitoring of a real tinlc basis. Paint s y stcnl operators monitor and audit the proccss.
Advantages of the Process
-
111 coo er'agc of complex shapes,
f? edges and corners, hanger brackets,
ground pads, and tank bottoms.
2. Access into partially closed areas, such as inside the
hanger brackets.
3. High solids film eliminates sagging problems.
4. Minimal orgLinic solvcnt content.
1 11ClLICIin
POWER PARTNERS
ANSI Standal'd C57.12.28 served as the benchmimrk for
perfornlance on the tests ]istcd below. The test results
clearly indicate the two-coat cathodic clectrodcpositic.ln
to be a leader in corrosion resistance, while maintaining
excellent performance in all areas of the ANSI stan(]amd.
"2Cf?C" passed 'Lill the tests listed here.
Salt Spray Test
Panels are scribal to bare metal and tested for 1000
hours in a 5% salt spray per ASTM 8117-85E1 and cvaluatcd per ASl'M D1654-79A. Loss of adhesion fn.)m bare
metal niLltit not exceed amore than 1;S" from the scribe.
Undcrfilnl corrosion must not exceed more than 1/16"
fR)nl the scribe.
Crosshatch Adhesion Test
Panels arc scribed to bare metal with a crosshatch pattern and tested per ASTM 1)3359-83. '1'llcrc m utit Inc.
100% adhesion to the bare nieta] and between lavers.
Humidity Test
Paint Pretreatment
1. Cc )I nlllctc and L1111fo1
ANSI C57.12.28 Performance Requirements
Pancl y must be tested for 1000 hours in accordance with
ASTM 1)2247-86A. 'There m Llst be no blisters.
Impact Test
'Petit panels wcrc impact((] per ASTM 172794-84 at 160 in.]b. c )f i mpact. 'Thee( must be not chipping of the paint
on the_ impact side of the test panel.
Oil Resistance Test
Oil resistancc testing, is condUctcc] at both 100C and
ambient for 72 hoots.'1'llcrc mutt Ibc no apparent
changes, such as color shift, blisters, loss of hardness, or
streaking.
Ultra violet Accelerated Wca thering Test
)
'lhst panels I1lLust be cxposcc] fell' 5l l ( Il(1L11S in accordance
with ASTM 153-84. Loss of gloss must not exceed 50% of
the original gloss as described in ASTM 1)523-85E1.
Abrasion Resistance—Taber Abraser Test
-
.I'hc total coating system 111L15t 13C tCtitcd using a CS-10
wheel, 1000-g1'.lnl weight, in accordance with ASTM
1)4060-84. The numhcr of abrasion 1 —. quired to wear the
coating through to thc substnitc nLJst be at lcast 3000
cycles.
The ANSI C57.120.28 test resLllts clearl y indicate the twocoat cathodic C]Cctrodcposition is a leader in corrosion
resistance while maintaining cxce]]ent performance in all
areas of the ANSI standard. The two-coat cathodic elcctrodcposition maintains consistent, L1nifo1'nl paint coveragc over the entire product, with nc) 1'Llns or sags, and
offering a sLJperior coating on dist1-ibution transformers.