Table of Contents
Advertisement
E) Parallel Wiring
The internal oring/isolation diode of the PM allows
parallel n+1 redundant wiring with no modification or
other external isolation de vices required. Figure 9 on
the following page illustrate some typical parallel wiring
schemes.
IMPORTANT: When wiring two or more units in parallel
d.c. wires for all units should be identical in gauge and
length and the output voltage of each module should be
adjusted (as outlined below) in order to facilitate droop
load sharing.
Parallel Load Sharing Adjustment Procedures
Method 1:
1) Shut off all but one of the Power Modules and apply
a load equivalent to 1/2 of the rating for that unit (e.g.,
for model PM-12-40A apply a 20 amp load).
2) Connect a digital voltmeter to the test points on the
front of the power module at the "V OUT" and (+) and (-)
positions.
3) Verify that the output voltage is at the correct factory
setting (see Specifications section) or at the desired
system voltage. If adjustment is neces sary, use a small
flat tip screwdriver to turn the "OUTPUT VOLTAGE
ADJUST" potentiometer on the front panel until the
voltmeter reads the desired system output voltage.
4) Shut off the PM, turn on the next unit in the system,
and repeat steps 2 through 4 until all PM's in the system
have the identical "V OUT" output voltage.
Method 2:
1) With all Power Modules powered up, apply the
typical operational d.c. system load.
2) Using a clamp-on ammeter, measure the output
current of each PM in the system. If there is an out-
put current differential of greater than 5 % between
any two PM's, attach the ammeter to the PM with
the highest output current and turn the "OUTPUT
VOLTAGE ADJUST" potentiometer on that unit slowly
counterclockwise, until the output current of that unit
reduces slightly.
3) Repeat step 2 until there is less than 5 % current
output differential between all PM's in the system.
F) Chassis Grounding
If grounding of the PM chassis is required for the
installation, use the provided 1/4" grounding stud on the
rear panel for this purpose (see Figure 2 or 3).
5
P.O. Box 1306
Newport Beach
California 92663
FIGURE 6: Parallel (two to three Power Modules)
and N+1 redundancy, negative ground
Power Module #1
Power Module #2
<
(+) Positive to
Distribution Panel
<
or Battery (fuse at
battery per N.E.C.
<
or local codes)
Power Module #3
V) Operation
A) AC Input
The PM will operate on 90-264 VAC input at 47-63 Hz. No input voltage selection or
adjustment is required for 115/230 VAC, 50 or 60 Hz. operation.
AC input is protected against over-current and internal short circuit condi tions by the circuit
breaker/input power switch on the front panel. When this switch is in the on position and
DC is available at the output terminal, the "ON" indicator L.E.D. on the left side of the front
panel will illuminate.
B) DC Output
The PM produces 12 VDC nominal output. The ground reference may be positive, negative
or floating.
Regulation: Regulation at the "V OUT" output terminal is within ± 2 % of rated voltage,
under all line and load conditions. Regulation at the "V2" terminal is ± 1 %. Ripple is within
± 1 % of rated voltage with or without batteries on-line.
Output Voltage Adjust: Factory-set voltages (as measured at the V OUT terminal) and
approximate adjustment ranges are specified below. Adjust ment is made at the "OUTPUT
VOLTAGE ADJUST" pot on the left side of the front panel using a small flat tip screwdriver
(see Figure 1). Output voltage test points for both the "V OUT" and "V2" outputs are
provided beside the voltage adjust pot for ease of monitoring while making this adjustment.
Use of a digital multimeter is recommended when making this adjustment. If the PM has
had the charger function board installed, output voltage adjustments are automatic and this
adjustment pot is disabled.
• • •
•
○ ○
E-Mail: techservice@newmarpower.com
(-) Negative to
Loads or
>
Battery
Phone: 714-751-0488
Fax: 714-957-1621
Advertisement
Table of Contents
