Special Analog Inputs; Oxygen Sensor Special Analog Input; Coolant Level Special Analog Input; Ac Voltage Sensing Inputs - Generac Power Systems Power Zone Pro Owner's Manual

Analog ground pins are provided for this purpose. Three
wire sensors are usually 4-20 mA or voltage type
sensors. #18 gauge wires are recommended for these
connections.

Special Analog Inputs

There are two special "fast" analog inputs; one reserved
for the input from an oxygen sensor, and another to read
a governor feedback signal. These inputs can be used for
other purposes when an external CAN type governor is
used or an oxygen sensor is not used. The channels are
read directly and not multiplexed. #18 gauge wires are
recommended for these connections. These inputs do
not support 4-20 mA signals.

Oxygen Sensor Special Analog Input

Oxygen sensors produce a 0-1 V input with potentially
fast transitions. The oxygen sensor can be selected to be
read through channel 2 of the special analog inputs. The
resolution is approximately 0.25 mV. The sensor is
usually self powered. #18 gauge wires are recommended
for this connection.

Coolant Level Special Analog Input

The coolant level sensor needs special treatment to
prevent surface electrolysis. Its voltage supply polarity
needs to be continually alternated. The circuit is
designed to accommodate a two wire resistive sensor
(part no. 0H1827) but other resistive sensors can be
used if they have a nominal resistance of 562K ± 6K. #18
gauge wires are recommended for this connection.

AC Voltage Sensing Inputs

The high voltage sensing inputs have a separate
connector which includes pins for generator voltage
sensing, utility voltage sensing, and neutral connections.
Wiring to these pins should be routed away from other
connectors to reduce the effects of electrical noise. The
voltage readings need to be calibrated for maximum
accuracy (see Voltage and Current Sense Input
Calibration). #18 gauge wires are recommended for
these connections.
NOTE: Check the fuses on the voltage sensing wires if
there are any voltage sensing issues and replace if
necessary.

AC Current Sensing Inputs

The generator current is measured through the use of
Current Transformers (CT's). These need to be
appropriately sized for the generator. The CT should be
rated for 300% of the generator rated current (example:
100 amp CT must be able to measure at least 300 amps)
Owner's Manual for Power Zone Pro Main Controller
to accommodate the 300% current limiting feature. Care
must be taken to correctly install the CT on the proper
phase, in the proper orientation, and using the proper
sense wire polarity. Failure to do so will cause erroneous
power readings. #18 gauge wires are recommended for
these connections. Typical connections for a generator
installation are shown in the
and AC Current Sensing
Installation and Operation
AC Voltage Sensing Inputs
Inputs.
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