The 40350 series automatic transfer switch (ATS) has many different protective features
to protect your coach from low quality power. Included in these are protection against high
voltage, low voltage, and an incorrectly connected chassis ground. If one of these fault
conditions is encountered, the ATS will open both contactors in order to protect the coach.
Once the fault condition goes away, the ATS will delay for approximately 2.5 minutes before
trying to close the appropriate contactor again.
If the ATS fails to close the contactor or transfer when expected, check the 40350 display
to see if an error message is displayed. The screen will ash an error message for that
failure such as “Loss of Ground”, “High Volt”, or “Reverse Polarity”. The error condition must
be corrected in order for the transfer switch to function correctly. Refer to the table on the
following page for help in troubleshooting these conditions.
If there is no error message and the display instead reads “Delay Active” this means that the
fault condition has cleared and that the switch is going through a 2.5 minute delay before
it will attempt to close the contactor again. Wait until this delay is over to see if the ATS
correctly closes its contactor.
If no display is available, check the level of the input voltage to ensure it is within the proper
operating limits. Also check that the ATS is correctly connected to chassis ground and that
the neutral conductor is correctly connected to ground at the power pedestal. Wait 2.5
minutes to check if the fault condition was temporary and has cleared. If so, the contactor
will pull in at the end of the 2.5 minute period.
CAUTION: To avoid damage to the transfer switch or the RV, the torque specications
TROUBLESHOOTING GUIDE
Model 40350 RVC
Automatic Transfer Switch
PROBLEM TROUBLESHOOTING STEPS
Unit does not engage shore
contactor when shore power
is present after 10 seconds.
• If available, check the 40350 display screen to see if an error message is displayed. Refer to Table 2 for
further troubleshooting.
• Check the input power at the RV pedestal. If the power is outside of the range of 102-132V, the unit will
protect the RV by not engaging the contactor. Move to a different source of power that is within the correct
limits.
• Check to make sure that the incoming power is within 55-70 Hz in frequency.
• Check to make sure that the incoming neutral is at the same voltage as the green incoming ground wire.
• Double check all wiring connections into the ATS and make sure that they are all properly torqued down.
Unit does not transfer to
generator power correctly
when the generator is
turned on.
Note that the ATS takes approximately 50 seconds to complete the transfer from shore power to generator power
after the generator is started. If this amount of time has passed and the generator contactor still does not engage,
check the following:
• If available, check the 40350 display screen to see if an error message is displayed. Refer to Table 2 for
further troubleshooting.
• Check the voltage level on the incoming generator lines. If the power is outside of the range of 102-132V,
the unit will protect the RV by not engaging the contactor. Refer to generator documentation to x incoming
voltage within acceptable limits.
• Check the incoming generator circuit breaker to ensure it is not tripped.
• Check to make sure that the incoming power is within 55-70 Hz in frequency.
• Verify that the incoming neutral is at the same voltage as the green incoming ground wire.
• Double check all wiring connections into the ATS and make sure that they are all properly torqued down.
For technical assistance, please call 1-800-780-4324 x 20311
TECHNOLOGY RESEARCH, LLC A Southwire Company
5250 140th Avenue North ▪ Clearwater, Florida 33760
505-00114A
on the terminal block cable installation diagram MUST be followed. Make sure that the screws holding the input and output power cables down to the
terminal block are fully tightened to the correct torque. Failure to fully tighten these connections could cause an electrical shock or re hazard. Care
must be taken to assure that the terminal screws are not cross threaded, otherwise an improper torque will result.
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