Download Section E. Power Supply Unit

SECTION E. POWER SUPPLY UNIT
E·,
Section E. Power Supply Unit
Description
The 7715 power supply unit is a rack-mount module for use
with Compumotor's range of brushless seIVO and stepping
motor cb1ves. The unit accepts a s1ngle- or three-phase AC
Snput and provides a single DC output voltage. Input and
output are sent via connections to a motherboard. which 1s
mounted on the rack and connected to the power supply. The
motherboard also carnes the AC line fuses. two AC line
suppression capadtoni. and a DC supply bleed resistor.
AddiUonal circuitry Sn the power supply dumps power
generated by the motor during deceleration. The max1mum
power dump ratlng is 68 watts continuous. In hJgh duty cycle
applications. this rating may need to be increased.
Provisions have been made for the addition of an external
dump reSistor (contact Compumotor for more information).
The module can power up to three rack-mounted drtves.
depending on the total maxfmum current demand.
Adequate venUlation for the power supply unit should be
provided. Rack-mounted systems usually require a cooling
fan. depending on the max1rnum load. A built-in fan tray.
With fans tnstalled as necessary. is an avallable option with
the Compumotor-suppl1ed rack.
Specifications
Table E-l provides the specifications for the power supply
unit.
P.r.meter
AC Input
DC Output
VA Rating
SDeclfic.tlon
50 - 107V rms. single or three phase
70 -150VOC
Single-phase input: 2200VA at 107V
Three-phase input: 3400VA at 107V
Max. Ambient Temperature 95°F (45OC)
Power Dump Current
11Almaximum)
Power Dump Rating
68 Watts continuous (provision for high-power
external dump resistor if reQuired)
Dimensions
3U!12HP
Weight
2 Ibs (0.9 Kgs)
Table E- i. Power Supply Specifications
E-2
SYSTEM 7 USER GUIDE
Fuse Ratings
Table E-2l1sts the power supply module fuse ratings and
types. Figure E-l shows the location of the fuses. In the event
of a failure. use only the spec1fled fuse types for replacement.
Fu ••
Location
R.tlng
FS1
FS1
FS2
FS3
Power Supply Module
PS Motherboard
PS Motherboard
PS Motherboard
2A llHB3Z mm
Table E-2. Location & Ratings
II
II
II
C=::J
PSI
CJ
II
o
II
D
II
FS2
FS3
CJ
0
D
II
II
II
II
II
II
II
II
II
DD
II
FSI
Figure E-l. Fuse LocaUon
25A OA HB 32 mm
25A OA HB 32 mm
2SA OA HB 32 mm
SECTION E. POWER SUPPLY UNIT
Installation
E-3
The power supply module Is nonnally suppUed as part of a
complete rack system. If this is not the case. and you are
mounting the power supply separately. you should observe the
following precautions:
•
•
•
•
•
Handle the unit With care.
Install the unit in a clean. dry. well-ventilated area.
Do not mount the unit on a hot surface.
Do not mount the unit above a radiant heat source.
The ctrculattng air must be free from steam. chemical
substances, combustible vapors. and oil.
Allow adequate venUlatlon above and below the rack. In
some applications tnvolvtng high duty cycles. additional
dump resistors may be needed as described earlier in this
chapter.
Connections
You will need to make the following connections to the power
supply module via the power supply motherboard.
DC Output
The DC output is taken via a pair of standoffs mounted on the
power supply motherboard. Normally. the connection.
between the power npply aDd the rack-mounted modulea are
done for ,.au.
AC Input
The AC input to the power supply unit may be either slngle- or
three-phase. Connection should be made between the power
supply motherboard and the isolating transformer in
accordance with the Instructions in Section D. Isolating
Transjonner.
When m.aJcinQ connections between the power supp~ and the
fsolatinQ ~ormer ,or drWe modrclls. be sure to use the
app apr iat.e JIClUIIe t6wire.
HV Supply
Indicator
A single green LED illuminates on the front panel to Indicate
the presence of the HV supply.
SYSTEM 7 USER GUIDE
E·4
Figures E-2 and E-3 show the c1rcult diagrams of the power
supply unit and its motherboard.
Principles of
Operation
The AC input is rect1fled by the two bridges BRI and BR2 and
smoothed by capadtors C 1 - C4. to provide the main HV
supply. Additional smoothing is provided by capacitors
mounted on the drive motherboards. When HV is present. the
front panel LED w1ll1llum1nate. The power dump circuit will
remain operative if one of the input fuses fails wl)en a three·
phase supply is used.
The remainder of the drcwtry absorbs power generated by the
motor while It IS deceleration. Dur1ng deceleration. the motor
generates power that causes the HV voltage to rise. If the HV
voltage rises above the reference voltage (158V). the power
dump drewt will be turned on and current will flow through
the dump resistors (R8 • Rll) until HV is restored to its
nominal value. The dump fuse. FSI. IS included to protect the
dump resistors and the circuit from over-dissipation. If this
fuse is blown and Is nOlt replaced. the driVe may be damaged.
When the AC power is switched off. the dump circu1t becomes
operative. redUCing the HV supply to about 30V Within 5
seconds.
FS,
210 32 mmTl HS
,
~........_
0
AC'
C---~----~'-~----~
D..M'
CIRCUIT
AC2
C3
C1
C.
C2
32w
Con_.
~..,
HI! SUPPl V ON LED
AC3
32
o0
FJgure E-2. Power Supply Circuit Diagram
... OUUP RES 2
SECTrON E. POWER SUPPLY UNIT
E-5
FSI 25A 32 mm QA ~
LI
O~""I-cI-CQ..~~---...t==~r
FS2 2SA 32 mm QA He
L2
_----G
C2
32 . .y
ConrwClOf
RI22IInZW
fN
DUMP RES I
_===~
o
[)IMP RES 2 - - - - 0 0
L3
FS3 25A 32
mm QA He
Figure E-3. Power Supply Motherboard C1TCutt Diagram
Summary
You should now have an understanding of the operation of the
power supply circuit. You should be able to adjust the
isolating transformer tappings to suit your supply voltage and
to provIde the required output voltage. If a fault occurs. refer
to Section K. Maintenance & Troubleshooting.