E) Parallel Wiring; F) Chassis Grounding - NewMar PM-24-80 Installation And Operation Manual

To minimize line loss at lengths greater than 5 feet, it is
recommended to increase wire size one gauge for each additional
5 feet of cable run. Positive and negative ground applications (with
battery) – follow wiring diagrams in Figures 4 & 5.
Note: Install output terminal cover.
FIGURE 4: Single Power Module, positive ground,
with battery:
OUTPUT VOLTAGE:
48 VOLTS
MAX OUTPUT CURRENT:
50 AMPS
(-) Negative Load or
–
Distribution Panel
FIGURE 5: Single Power Module, negative ground,
with battery:
OUTPUT VOLTAGE:
48 VOLTS
MAX OUTPUT CURRENT:
50 AMPS
(-) Negative Load or
Distribution Panel
5
P.O. Box 1306, Newport Beach, California 92663 • Phone: 714-751-0488 • Fax: 714-957-1621 • E-Mail: techservice@newmarpower.com P.O. Box 1306, Newport Beach, California 92663 • Phone: 714-751-0488 • Fax: 714-957-1621 • E-Mail: techservice@newmarpower.com
DC AC
OUTPUT INPUT
FAIL FAIL
OK
OK
C C
STATUS
CONTACTS
NEWPORT BEACH, CA. USA
GND
(+) Positive to
Load or Ground
Bus Bar
* Typical; Fuse per
*
N.E.C. or local codes
+
Battery
DC AC
OUTPUT
INPUT
FAIL FAIL
OK OK
C
C
STATUS
CONTACTS
NEWPORT BEACH, CA. USA
GND
(+) Positive to
Load or Ground
Bus Bar
*
* Typical; Fuse per
–
+
N.E.C. or local codes
Battery
www.newmartelecom.com www.newmartelecom.com

E) Parallel Wiring

The internal oring/isolation diode of the PM allows parallel n+1
redundant wiring with no modification or other external isolation
devices required. Figures 6-7 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:
TEMPERATURE
1) Shut off all but one of the Power Modules and apply a load
PROBE
INPUT VOLTAGE: 230 V @ 22 A, 50 - 60 Hz
equivalent to 1/2 of the rating for that unit (e.g., for model PM-
48-50 apply a 25 amp load).
2) Connect a digital voltmeter to the test points on the front of
the power module.
3) Verify that the output voltage is at the correct factory setting
(see Specifications section) or at the desired system voltage. If
adjustment is necessary, 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 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 output 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.
TEMPERATURE
3) Repeat step 2 until there is less than 5 % current output
PROBE
INPUT VOLTAGE: 230 V
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). Note: The PM chassis is floating from DC
output but can be grounded positively or negatively
@ 22 A, 50 - 60 Hz