Generac Power Systems R-200A User Manual

 8 

If the R-200A controller does not receive a signal 
from the engine flywheel sensor, the R-200A control-
ler cannot maintain the generator output frequency 
or monitor for an overspeed condition. If this sig-
nal is lost the R-200A controller will shut down the 
engine as follows:

The engine control board (R-200A controller) will 
monitor the engine speed signal during engine crank-
ing. If the control board does not see a valid signal 
within the first four seconds of each crank cycle it 
will stop the crank cycle, lock out on a shut down 
fault and flash the overspeed LED.

Running mode is handled differently because there 
is always the possibility the engine could slow down 
or stop running due to a temporary overload. To 
avoid shutting down and latching out on a temporary 
problem the following is done. If the engine is up and 
running, and the control board stops receiving a valid 
engine speed input signal it will respond as follows:

1.  It will close the throttle.
2.  It will shut down the engine by turning off the fuel 

supply.

3.  It will wait for 15 seconds to ensure the engine 

has stopped.

4.  It will then energize the starter and monitor the 

engine speed signal.

A.  If the control board does not see the engine 

speed signal it will stop the crank cycle, lock out 
on fault, and flash the overspeed LED.

B.  If the control board does see the engine speed 

input signal during cranking it will start and run 
the engine normally. If the engine speed signal is 
again lost while running it will repeat the above 
procedure one more time.

C.  If the failure should repeat a third time, the con-

trol board will shut down the engine, lock out on 
fault, and flash the over speed LED.

Occurs if the engine has not started within the total 
90 second crank cycle. This is a latched fault and will 
shut down the engine.

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All five (5) RED LED’s on the front panel will be ON 
all the time if DIP switch position 5 is not set cor-
rectly.

When the generator is shut down on a latched fault or 
latching alarm, the AUTO/OFF/MANUAL switch must 
be set to the OFF position to turn off the correspond-
ing fault LED. Prior to moving the switch to the OFF 
position, record which LEDs are ON or FLASHING 
and the date on the back cover of this manual.

When this generator, along with an RTS-type or HS-
type automatic transfer switch has been installed and 
connected, a circuit board in the generator control 
panel constantly monitors the utility voltage and con-
trols the operation of the transfer switch.

To implement this mode of operation, Position 2 of 
the eight-position DIP switch, which is located on the 
generator circuit board (see Figures 1 and 2), must 
be in the OFF position. In ATS Mode utility voltage 
sensing, weekly exercising, and load transferring is 
under the control of the generator.

Should the utility voltage drop below a preset value, 
and remain at this low voltage for a preset amount 
of time, the generator cranks and starts. After the 
generator starts, the transfer switch transfers the 
load circuits to the generator so the generator can 
power them. When the utility source voltage has been 
restored, the transfer switch re-transfers the load 
circuits back to the utility source voltage and the gen-
erator shuts down.

The transfer switch is controlled by the generator 
circuit board via control wires 23 and 194. Wire 23 
connects the collector of an NPN transistor on the 
generator circuit board to the “low side” (Terminal 
23) of the transfer relay coil in the transfer switch. 
Wire 194 connects positive battery voltage from the 
generator circuit board to the “high side” (Terminal 
194) of the transfer relay coil in the transfer switch.

In order for the generator utility voltage sensing 
function to work, it is necessary to provide a 5 amp 
fused 240VAC for 240V or 480V systems or 208VAC 
utility source connection (depending on the generator 
being used) from the transfer switch main N1 and N2 
terminals to the generator wiring panel N1 and N2 
terminals (See Figure 4).