PROCESS DESCRIPTION
Gentherm Global Power Technologies
Page 17
Current Limiter:
Over load protection triggers when the load draws excess current. The
result is a proportional drop in output voltage, fold-back current limiting. Short circuit
protection is also designed into the C/L. A 15 second short circuit will not damage the
generator or the C/L.
CAUTION!
If extended short circuit durations are anticipated, an
in-line fuse should be placed on the output of the
limiter converter. Use 10 A slow blow for the model
P-5100-12 or a 5 A slow blow for the model P-5100-
24 TEG.
Voltage Sensing Relay:
Two independent Voltage Sensing Relays (VSRs) provide a set of
contacts to indicate an alarm condition when the output voltage drops below a preset
minimum. Low voltages, due to overloads, lack of fuel or a faulty generator, are detected by
a voltage sensing circuit incorporated into the voltage limiter. When a low voltage condition
is detected, the Voltage Sensing Relay (VSR) with connections NC (normally closed), NO
(normally open) and COM (common) can be used to trigger an alarm or other processes.
When the generator is above the trip voltage the connection between NO and COM is closed
and the connection between NC and COM is open. If the generator is below the trip voltage,
then the connection between NO and COM is open and the connections between NC and COM
is closed. The trip voltage is adjusted by the pot labeled VSR 1 and VSR 2 adjust on the
Limiter board.
On Board Current Sense:
The C/L includes an onboard current sense that measures the
customer load current. The output is across pin 3 (+) and pin 2 (-) of the J-vsg1 connector
on the Regulating Limiter Board (see Figure 7) and is scaled at 100mV/A. The current sense
has an accuracy of 10%. If the Remote VSR Terminal Block is installed the current sense
output can be measured across TB3 7 (-) and 8 (+).
Power Resistor:
When no load, or a very small load, is connected the TEG has more power
available than needed by the load. This excess power is directed into a power resistor by the
voltage limiter.
4.3
TEMPERATURE COMPENSATION
When required for charging lead acid batteries, temperature compensation can be enabled
to allow the output voltage to vary with temperature. The output will be adjusted by
approximately 5.5mV per Cell per ºC (33mV/ºC for the 12V Setting, 66mV/ºC for the 24V
setting).
