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Transcript
Cummins Rocky
Mountain
Electrical Safety Procedure:
PARALLEL LOAD BANK TESTING
ISOLATED BUSS
Number:
ESP-15
Revision:
0
Date:
July 12, 2006
Page:
1 of 11
1. PURPOSE
The purpose of this practice is to provide guidance for the proper and safe
performance of parallel load bank testing on gensets. This practice will also identify
the hazards presented by load bank testing and provide guidance with regard to the
proper safe work procedures and personal protective equipment (PPE) required to
protect Cummins Rocky Mountain (CRM) qualified electrical workers.
2. SCOPE
This policy applies to qualified CRM electrical workers who perform parallel load
bank testing of gensets. The information included in this policy is taken from the
OSHA Electrical Safe Work Practices standard (29 CFR 1910.333) and the National
Fire Protection Association (NFPA 70E-2004), which is considered an industry “best
practice” for electrical safety.
Note: This procedure should not be performed on any genset located outdoors during
rainy weather or when the ground at the work area is saturated with water (i.e., large
water puddles).
3. DEFINITIONS
There are a number of definitions that must be understood to properly apply this
procedure. A complete listing of the definitions can be found in the CRM Electrical
Safety Program.
4. ELECTRICAL HAZARDS
CRM electrical workers are exposed to three principal electrical hazards during load
bank testing and include:
a) Shock;
b) Arcs; and
c) Blast.
Electric Shock- Electrical shocks result in internal burning of tissue caused by
electric current (measured in amperes) flowing through the body. The loss of tissue
continues for as long as one week after the shock itself and usually results in either
debilitating injuries or death.
The most effective PPE for electric shock entails placing some form of insulating
material between the worker and electricity. The most common types of PPE used
Cummins Rocky
Mountain
Electrical Safety Procedure:
PARALLEL LOAD BANK TESTING
ISOLATED BUSS
Number:
ESP-15
Revision:
0
Date:
July 12, 2006
Page:
2 of 11
for shock protection include approved insulating rubber gloves with leather protectors
and Class E hardhats.
Electric Arcs- Electrical arcs result in external burning of tissue caused by extreme
heating of the surrounding air when arc-energy is released. In addition, external
burns may also be caused by molten metal or insulation being expelled from electrical
equipment as a result of arc-energy being released. External burns caused by arcs are
by far the leading cause of electrical injuries and death.
The most effective PPE for electrical arcs entails donning materials capable of
absorbing the arc incident energy. This normally includes the use of Flame Resistant
(FR) clothing, hard hats, face shields and rubber gloves. See the Required PPE
section for more detailed information.
Arc-Blasts- Electrical arc-blasts are caused by rapidly expanding gases in the vicinity
of electric arcs. The injuries associated with arc-blasts include crushing of the body
by the concussions associated with explosions and puncture wounds caused by
projectiles (e.g., broken insulators, partially melted metal, etc.) driven through the
body by the energy of the blast. Effective PPE for arc-blasts is identical to that for
electric arcs.
5. REQUIRED PPE
All steps listed in the procedure require that safety glasses with side shields and
non-melting or untreated natural fiber clothing be worn (this is the minimum for
Hazard Class 0). Additional PPE depends on the task being performed. Table 1
summarizes the required PPE by Hazard Class. Each step lists the required PPE to
complete the task. The additional PPE can be removed when indicated in the text.
Shock Protection- For equipment rated at 600 volts or less, shock protection will
include Class 0 (rated up to 1,000 volts) rubber gloves with leather or goatskin
protectors. All metering equipment will be Category III rated or greater.
Note: It cannot be overstated that, unless definitive tests have been performed to
verify a zero energy state, the equipment must be treated as energized and rubber
gloves are required.
Arc-Flash Protection- For both high and low voltage units, arc-flash protection
includes FR Clothing rated at a minimum of 4-cal/cm2 and face shield rated at
8-cal/cm2.
Cummins Rocky
Mountain
Electrical Safety Procedure:
PARALLEL LOAD BANK TESTING
ISOLATED BUSS
Number:
ESP-15
Revision:
0
Date:
July 12, 2006
Page:
3 of 11
Table 1
Required PPE By Hazard/Risk Category
Hazard/Risk Hazard/Risk Hazard/Risk
PPE
Category 0 Category 1* Category 2
[HC0]1
[HC1]1*
[HC2]1
Safety Glasses with Side Shields
X
X
X
Non-Melting or Untreated Natural Fiber Clothing
X
X
X
2,3
FR Clothing (ATPV = 4)
X
Hearing Protection
X
2,4
FR Clothing (ATPV = 8)
X
Class 0 Rubber Gloves with Protectors
X
Face Shield (ATPV = 8) with Hard Hat
X
*
Modified.
HC – Hazard/Risk Category is defined in NFPA 70E-2004, Table 130.7(C)(9)(a).
2
Minimum Arc Thermal Performance Value in calories/centimeter squared.
3
FR shirt with FR pants or FR coverall.
4
Cotton underwear (shirt with shorts) plus FR shirt with FR pants or FR coverall.
1
6. PROCEDURE
Note: This procedure should not be performed on any genset located outdoors during
rainy weather or when the ground at the work area is saturated with water (i.e., large
water puddles).
The electrical safety boundaries for this procedure are provided in Table 2. The listed
hazard class (HC) indicates the level of PPE required to cross the boundary. The HC
value, in brackets, is also provided at then end of each step when applicable. Refer to
Table 1 for the required PPE.
Cummins Rocky
Mountain
Electrical Safety Procedure:
Number:
ESP-15
Revision:
0
Date:
July 12, 2006
PARALLEL LOAD BANK TESTING
ISOLATED BUSS
Page:
4 of 11
Table 2
Electrical Safety Boundary Distances
Boundary
Distance
Hazard Class
4-feet
HC1
3-feet 6-inches
HC1
Restricted Approach Boundary
1-foot
HC2
Prohibited Approach Boundary
1-inch
HC2
Flash Protection Boundary
Limited Approach Boundary
The PPE required to complete this task includes:
a) Class 0 electrical gloves with protectors;
b) FR clothing (ATPV = 4 [HC1], ATPV = 8 [HC2]);
c) Face shield (ATPV=8) with hard hat;
d) Leather work gloves;
e) Non-melting or untreated natural fiber clothing;
f) Safety glasses with side shields; and
g) Voltage testing meter (Category III rated or greater).
(BEGIN PROCEDURE)
STEP
(1)
REQUIRED PPE
TASK DETAILS
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Set up boundary area as appropriate. [HC0]
Cummins Rocky
Mountain
Electrical Safety Procedure:
Revision:
0
Date:
July 12, 2006
PARALLEL LOAD BANK TESTING
ISOLATED BUSS
STEP
Number:
ESP-15
Page:
5 of 11
REQUIRED PPE
TASK DETAILS
(2)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Leather Work Gloves
Disconnect negative (-) leads from batteries of
all gensets and lockout/tagout as needed. See
CRM ESP-04, Generator Battery Replacement,
for detailed instruction. The leather gloves can
be removed after the leads have been
disconnected and secured as needed. [HC0
Modified]
(3)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
FR Clothing (ATPV = 8)
Hearing Protection
Class 0 Rubber Gloves
with Protectors
Face Shield (ATPV = 8)
with Hard Hat
Locate and lockout/tagout load bank breaker at
paralleling switchboard. If no load bank breaker
is present identify switchboard buss location to
connect load bank cables. Locate any Generator
Main to load buss feeder breaker and
lock-out/tagout. [HC2]
(4)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
FR Clothing (ATPV = 8)
Hearing Protection
Class 0 Rubber Gloves
with Protectors
Face Shield (ATPV = 8)
with Hard Hat
Check voltage on all load bank breaker terminals
or at alternate buss connection point to ensure a
zero energy state using the 3-point voltage
testing procedure. The electrical gloves and face
shield can be removed once the zero energy state
is confirmed. [HC2]
Note: The 3-point voltage check is not required
when the genset has no other external electrical
connections and the battery has been
disconnected.
Cummins Rocky
Mountain
Electrical Safety Procedure:
Revision:
0
Date:
July 12, 2006
PARALLEL LOAD BANK TESTING
ISOLATED BUSS
STEP
Number:
ESP-15
Page:
6 of 11
REQUIRED PPE
TASK DETAILS
(5)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Ensure load bank is properly grounded. This
includes both equipment grounding and system
grounding connections. [HC0]
(6)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Leather Work Gloves
Inspect the cables for defects, such as cuts,
abrasions, or burned contacts. Pay particular
attention to the terminations and the contacts. If
any defects are found, the cable must be tagged,
taken out of service, and reported to the local
field service dispatcher to ensure it is repaired
prior to the next load bank test. [HC0 Modified]
Note: Ensure there are enough cables and that
they are properly sized for the load test to be
performed. Use 2/0 cable for up to 265 amps or
4/0 cable up to 360 amps.
Cummins Rocky
Mountain
Electrical Safety Procedure:
Revision:
0
Date:
July 12, 2006
PARALLEL LOAD BANK TESTING
ISOLATED BUSS
STEP
Number:
ESP-15
Page:
7 of 11
REQUIRED PPE
TASK DETAILS
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Leather Work Gloves
Layout all cables in sets of three, one set per
phase. Do not group cables of the same phase
together. All cables must be color coded by
phase or use phase tape on cable ends. Ensure
that all cables are properly color coded and equal
length before connecting them. The leather
gloves can be removed once all the connections
have been made. Protect the cable from any
sharp edges. [HC0 Modified]
REQUIRED PPE
TASK DETAILS
(8)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Barricade the cable run from the switchboard to
the load bank to prevent unqualified persons
from approaching the cables (e.g., signs, safety
cones, caution tape, etc.). [HC0]
(9)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Ensure all breaker and panel covers are properly
installed on both the gensets, switchboard, and
the load bank. [HC0]
(7)
STEP
Cummins Rocky
Mountain
Electrical Safety Procedure:
Revision:
0
Date:
July 12, 2006
PARALLEL LOAD BANK TESTING
ISOLATED BUSS
STEP
Number:
ESP-15
Page:
8 of 11
REQUIRED PPE
TASK DETAILS
(10)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Ensure all load bank switches are in the
“Open/Off” position. Select correct voltage for
load bank controls. [HC0]
(11)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Remove lockout/tagout device from load bank
breaker. [HC0]
(12)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Leather Work Gloves
Remove lockout/tagout device from battery leads
and reconnect. See CRM ESP-04, Generator
Battery Replacement, for detailed instruction.
[HC0 Modified]
(13)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Leather Work Gloves
Hearing Protection
Ensure load bank exhaust is properly routed to
avoid personal injury and damage to property
(e.g., avoid closed areas and sprinkler heads used
for fire suppression). [HC0 Modified]
(14)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Leather Work Gloves
Start gensets and close load buss. [HC0}
Cummins Rocky
Mountain
Electrical Safety Procedure:
(15)
Revision:
0
Date:
July 12, 2006
PARALLEL LOAD BANK TESTING
ISOLATED BUSS
STEP
Number:
ESP-15
Page:
9 of 11
REQUIRED PPE
TASK DETAILS
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
FR Clothing (ATPV = 8)
Hearing Protection
Class 0 Rubber Gloves
with Protectors
Confirm voltage as required. The electrical
gloves and face shield can be removed once
voltage testing is complete. [HC2]
Face Shield (ATPV = 8)
with Hard Hat
(16)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Leather Work Gloves
Hearing Protection
Add loads as appropriate. Check amperage on
each cable to ensure none are overloaded. Watch
for hot spots at crimped cable ends or cam locks.
[HC0 Modified]
(17)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Leather Work Gloves
Hearing Protection
Shut down gensets per manufacturer’s shutdown
procedure. Hearing protection can be removed
once testing is complete. [HC0 Modified]
Cummins Rocky
Mountain
Electrical Safety Procedure:
Revision:
0
Date:
July 12, 2006
PARALLEL LOAD BANK TESTING
ISOLATED BUSS
STEP
Number:
ESP-15
Page:
10 of 11
REQUIRED PPE
TASK DETAILS
(18)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Leather Work Gloves
Disconnect negative (-) battery leads and
lockout/tagout as appropriate. See CRM
ESP-04, Generator Battery Replacement, for
detailed instruction. The leather gloves can be
removed after the leads have been disconnected
and secured as needed. [HC0 Modified]
(19)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
FR Clothing (ATPV = 8)
Hearing Protection
Class 0 Rubber Gloves
with Protectors
Face Shield (ATPV = 8)
with Hard Hat
Lockout/tagout load bank breaker. [HC2}
(20)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
FR Clothing (ATPV = 8)
Hearing Protection
Class 0 Rubber Gloves
with Protectors
Face Shield (ATPV = 8)
with Hard Hat
Check voltage on all loadbank voltage terminals
to ensure a zero energy state using the 3-point
voltage testing procedure. The electrical gloves
and face shield can be removed once the zero
energy state is confirmed. [HC2]
Note: The 3-point voltage check is not required
when the genset has no other external electrical
connections and the battery has been
disconnected.
Cummins Rocky
Mountain
Electrical Safety Procedure:
Revision:
0
Date:
July 12, 2006
PARALLEL LOAD BANK TESTING
ISOLATED BUSS
STEP
Number:
ESP-15
Page:
11 of 11
REQUIRED PPE
TASK DETAILS
(21)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Leather Work Gloves
Remove cabling from switchgear to load bank.
Re-inspect the cables for defects, such as cutting,
abrading or burned contacts. Pay particular
attention to the terminations and the contacts.
Any defects should be tagged and reported to
CRM supervision to ensure it is repaired prior to
the next load bank test. [HC0 Modified]
(21)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Leather Work Gloves
Remove lockout/tagout from battery leads and
reconnect leads. Remove lock-out/tag-out from
load bank breaker. The leather gloves can be
removed after the leads are reinstalled. [HC0
Modified]
(22)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Hearing Protection
Start the gensets per the manufacturer’s start up
checklist. Check for proper unit operation by
ensuring that the unit starts and verify through
control metering. [HC0 Modified]
(23)
Safety Glasses with Side
Shields
Non-Melting or
Untreated Natural Fiber
Clothing
Hearing Protection
Shut down gensets per manufacturer’s shutdown
procedure. Hearing protection can be removed
once testing is complete. [HC0 Modified]
(END PROCEDURE)