HomeControllersTransfer Switch

Transfer Switch Controller

The Transfer Switch is a generator-set controller. It is used on generator sets from Cummins/Onan, including the 20GSBB-6714, C13N6H, C17N6H and C20N6H.

11
Generator sets
Cummins/Onan
Brand
10–18 kW
Power range
3
Fuel types

Generator sets using this controller

11

Also fitted to: Cummins/Onan 14GSBB-6716A/B, Cummins/Onan 20GSBB-6713A/B.

Engines paired with this controller

1

Troubleshooting

49

Fault codes

CodeMeaningCauseRemedy
12Overvoltage
12Overvoltage - Fault Code 12
13Undervoltage
13Undervoltage - Fault Code 13
14Overfrequency
14Overfrequency - Fault Code 14
15Underfrequency
15Underfrequency - Fault Code 15
19Governor Actuator Shutdown
19Governor Actuator shutdown - Fault Code 19
2Low Oil Pressure Fault
2No AC Power - generator set Running, Status LED On Steady or Flashing
22GOVERNOR ACTUATOR OVERLOADDuration of operation at or near full duty−cycle beyond design limitReduce the number of connected loads especially loads that require higher starting current such as air conditioners. Check and service air filter as necessary. Have unit serviced by an authorized Cummins Onan dealer.
22Governor Actuator Overload
22Governor Actuator Overload - Fault Code 22
27VOLTAGE SENSE LOSTControl unable to sense output voltageHave unit serviced by an authorized Cummins Onan dealer.
27Voltage Sense Lost
27Voltage Sense Lost - Fault Code 27
29High Battery Voltage
29High Battery Voltage - Fault Code 29
3Service Check Fault
32LOW CRANKING SPEED SENSEController sensed generator set cranking speed less than 180 rpm for greater than 3 seconds.Clean and tighten positive (+) and negative (−) battery cable connections at the battery. Recharge or replace battery. Refer to the battery manufacturer’s recommendations. Verify engine oil viscosity is correct for the ambient temperature. If not, refill and replace engine oil with correct viscosity. Have unit serviced by an authorized Cummins Onan dealer.
32Low Cranking Speed Sense
32Low Cranking Speed Sense - Fault Code 32
35Control Card Failure
35Control Card Failure - Fault Code 35
36GENERATOR SET STOPPED WITHOUT FAULT CONDITIONGenerator stopped without command by controller.Open any closed fuel valves. Secure spark plug leads to spark plugs. Check and service air filter as necessary. Replace spark plugs. Check for mechanical damage.
36Generator Set Stopped Without Fault Condition
36Generator Set Stopped Without Fault Condition - Fault Code 36
37Invalid Set Configuration
37Invalid Set Configuration - Fault Code 37
4Overcrank
43Processor Fault
43Processor Fault - Fault Code 43
45SPEED SENSE FAULTController unable to sense quadrature frequency.Have unit serviced by an authorized Cummins Onan dealer.
45Speed Sense Fault
45Speed Sense Fault - Fault Code 45
46GENERATOR SET OVERLOADCurrent is at 100% of rated operation at design limit.Reduce the number of connected loads especially loads that require higher starting current such as air conditioners. Check and service air filter as necessary. Have unit serviced by an authorized Cummins Onan dealer.
46Generator Set Overload
76Alternator Over Temp
78Low Fuel Pressure
79Failure To Transfer To Generator Set
CODE 19Controller sensed governor actuator circuit open or shorted.Have unit serviced by an authorized Cummins Onan dealer.

Symptoms & remedies

SymptomCauseRemedy
GENERATOR SET CRANKS BUT DOES NOT START − NO FAULT CODENot holding start switch long enough to cause fault1. Check and record last fault code. 2. Crank generator set and hold switch until control stops cranking and displays fault code (approximately 30 seconds): troubleshoot fault code and reference last fault code recorded above if necessary.
GENERATOR SET RUNS BUT STOPS WHEN SWITCH IS RELEASED − NO FAULT CODENot holding start switch long enough to cause fault1. Check and record last fault code. 2. Start generator set and hold switch until control shuts down and displays fault code (approximately 30 seconds): troubleshoot fault code and reference last fault code recorded above if necessary.
NO AC POWER − GENERATOR SET RUNNING, STATUS LED ON STEADY OR FLASHING RAPIDLYCircuit breakers tripped to OFF, due to short circuit or overloading.1. Reset or turn on generator set circuit breaker. 2. Reset or turn on circuit breaker in the distribution panel. 3. Reduce number of loads. 4. Have the circuits from the generator set and distribution panel verified by an authorized electrician.
NO RESPONSE − STATUS INDICATOR LIGHT DEADLow/No battery voltage, poor battery connection, faulty battery, open harness connection, faulty start/stop switch, faulty LED1. Try generator set Start Switch if the remote display Start Switch does not respond, and vice versa 2. Clean and tighten positive (+) and negative (−) battery cable connections at the battery. 3. Recharge or replace battery. Refer to the battery manufacturer’s recommendations.
STARTER ENGAGES − DISENGAGESCranking voltage dips below 6 VDC − Battery connections, battery, charging system, start/stop switches1. Clean and tighten positive (+) and negative (−) battery cable connections at the battery. 2. Recharge or replace battery. Refer to the battery manufacturer’s recommendations. 3. Have the battery charger serviced by an authorized Cummins Onan dealer.
STARTING BATTERY RUNS DOWNMarginal battery connections, battery, charging system, excessive cranking1. Clean and tighten positive (+) and negative (−) battery cable connections at the battery. 2. Recharge or replace battery. Refer to the battery manufacturer’s recommendations. 3. Have battery charger serviced by an authorized Cummins location.

Fault codes and symptom→remedy steps extracted from this controller’s service/owner documentation; verify against the official manual before servicing. Aggregated from the service documentation of generator sets built on this controller.