SamplexPower SEC-4825BRM, Owner'S Manual

Page: 15 / 36

14 | SAMLEX AMERICA INC. SAMLEX AMERICA INC. | 15
SeCtION 3 | Design & Principle of Operation
not be able to function normally as Slaves and their associated LEDs “PSM x” will flash
randomly.
The output voltage of the common DC bus (before Schottky Diodes D1) will read the
higher voltage of this module.
The output voltage of each module measured at the module output pads under S-5
and S-6 (See fig.3.4) is factory pre-set at 55V to provide no load voltage of 54.8V at the
Load Terminals. A precision multi-turn potentiometer VR1 is provided for fine adjust-
ment of the output voltage of each of the modules. the adjustment range of module
output voltage is 53V to 56.3V.
If the output voltage of the modules is required to be set to a value other than the
preset value of 55V, the individual output voltage of each of the 5 modules will be re-
quired to be adjusted one by one to the same new “set voltage” within the adjustment
range of 53V to 56.3V. This is done by feeding AC input power to only the module
under adjustment and disconnecting AC input power to the other modules. Similarly,
during operation and during replacement of defective module with new module, the
output voltage of the all the individual modules will be required to be adjusted to the
desired value.
As explained under operation of Battery Back Up And charging Section on page 8,
although the output voltage of the module at terminals S5 and S6 (fig.3.4) or at the
common DC bus (before the Schottky Diode D1) is tightly regulated at the preset value
of 55V, the voltage at the output terminals Load (+) and Load (−) will vary due to the
forward voltage drop of the isolating Schottky Diode D1 and the drop along the DC
bus and wiring. Table 3.1 below gives details of voltage settings and actual voltages
available under no load and under loaded conditions.
tABLe 3.1 VoLtAGe SettinGS
Module output
Voltage at terminals
S5 and S6 (Fig 3.4)
Load current
(combined current of
5 paralleled Modules)
Forward Voltage drop
“Vf” Across Schottky
Diode D1
Voltage Available at
Load terminals Load (+)
and Load (−)
(Module Voltage - “Vf”)
Preset Voltage 55V
No load (0A) 0.2V 54.8V
15A 0.6V 54.4V
25A 0.8V 54.2V
Adjustment range:
53V to 56.3V
No Load 0.2V 52.8V to 56.1V
15A 0.6V 52.4V to 55.7V
25A 0.8V 52.2V to 55.5V
Procedure for Adjusting output Voltage of Modules
1. Switch off the unit and unplug the AC input power cord.
2. The output voltage of each individual module is adjusted one by one starting from
say, the left most module – PSM 1 and progressing to the right most module – PSM