OPERATIONAL TESTING
READ AND FOLLOW ALL SAFETY INSTRUCTIONS
I. Plug in the powercord. If the main panel circuit breakers are
switched on, RV load should operate normally. Unplug the
powercord.
II. Start the generator. There is a pre-programmed 20-30 sec-
ond delay in the transfer switch. The delay is designed to allow
the generator a brief warm-up period. When the delay completes
its cycle the switch should engage and the RV load should
operate normally. An audible click should sound as the switch
engages.
III. Shut down the generator. As the generator winds down the
switch should disengage without chatter or cycling. An audible
click should sound as the switch disengages.
IV. Plug in the powercord. Start the generator. After the pre-
programmed delay, the switch should transfer power automati-
cally from the powercord to the generator. Listen for the audible
click as the switch transfers, as there will likely be no other
indication that the switch has engaged. Shut down the genera-
tor and unplug the powercord.
V. On transfer switch arrangements with three power supplies,
plug in the powercord, start the generator, and turn on the in-
verter. With all three supplies energized at the same time, the
switch will select the generator for the primary supply choice.
Shut down the generator. The switch will transfer to the
powercord. Unplug the powercord. The switch will transfer to
the inverter. The inverter should always be connected so that it
is only selected in the absence of both the other supplies.
TROUBLESHOOTING
I. LOW VOLTAGE: Low voltage is harmful to most appliances.
Contactor-based transfer switches are also affected by low volt-
age; if the voltage level drops far enough the contactor points
will “chatter”. Sustained contact chattering can cause transfer
switch damage. Switches that have been damaged by chatter-
ing need to be returned to the factory for replacement.
GENERAL LOW VOLTAGE: Low voltage can be caused by
low voltage conditions such as an RV park with inadequate
wiring for crowded camper conditions where everyone’s elec-
tricity suffers (brownout). In this case a voltmeter will be help-
ful and will show a low voltage reading from the park recep-
tacle, even before the RV is plugged in. When you experience
general low voltage conditions, remember, that brownouts can
be harmful to most appliances. A better alternative might be to
utilize the generator until park voltage conditions improve.
LOCALIZED LOW VOLTAGE: Low voltage conditions can be
caused by specific situations such as an additional cord which
is too long and too small for the load. Do not attempt to extend
the RV powercord by using a 16 gauge 100 foot extension
cord, or any cord not rated for an RV-size load. A localized low
voltage condition will result when a load is turned on which is
larger than that which the cord is designed for. As soon as the
RV tries to draw more current than the amount for which the cord
is rated, the voltage will fall
within the length of the cord, and the
RV will experience low voltage. This is especially noticeable dur-
ing inrush current situations such as an air conditioner start-up.
Contactor-based transfer switches are affected by this. The
compressor will try to start, the voltage will drop, which will
cause the contactor to drop out, at which point the voltage
will rise to the pre-inrush level. The contacts will chatter when
the A/C compressor kicks in, however the voltage may read
normal. Most meters are not fast enough to record this volt-
age drop. You can test for low voltage readings during this
inrush cycle by reading voltage at the contactor terminals while
manually holding the contactor plunger down in its closed po-
sition. This will override the chattering condition and the meter
will have time to register the reduced voltage. If this condition
exists, identify and correct the low voltage situation before
proceeding further.
PHYSICAL INTERFERENCE: Some transfer switch mod-
els have wiring connections made by wire nuts on 6
″
leads.
Occasionally on these models, the wiring connections will
get folded into the can in such a manner that the wiring will
interfere with the physical operation of the relay. Visually
inspect for free operation of the relay(s).
TIME DELAY BYPASS SWITCH: The time delay function
in the control module on some models may be bypassed.
Relay-based transfer switches have incorporated into the
control module board a small switch which allows the tech-
nician to activate or bypass the time delay. The time delay
is necessary during generator start-up so that the genera-
tor does not have to start under load; the delay is not nec-
essary for powercords or inverters. Therefore in transfer
switch operation where the module is controlling a supply
other than a generator, the delay switch should be set to
the bypass (ON) position. This will allow instantaneous
switching. Another time for bypassing the delay is during
diagnostic and troubleshooting efforts; if bypassing the
delay causes the switch to work when it otherwise won’t,
then the time delay has malfunctioned and the board should
be replaced. To bypass the time delay, locate the switch on
the end of the circuit board and select the position on the
switch marked ON. Time delay bypass is now activated,
and transfer will be instantaneous.
FAILED TIME DELAY CONTROL MODULE: It is possible
for a voltage spike, etc. to cause the time delay module to
fail: if this happens the switch will no longer transfer. Transfer
Switch models have a diagnostic LED mounted on the con-
trol module circuit board. If the module is receiving 120 VAC
input and is operating properly, the LED will be lit. This means
the control module has timed for the 20-30 second delay and
is now providing power to the coil on the relay. If the module
input is energized and the LED does not light after 30 sec-
onds, the time delay function in the module has failed, and
the module should be replaced. To verify this, try setting the
time delay switch on the board to the delay bypass position;
the switch should transfer with no delay.
Note that this posi-
tion will allow emergency operation until the module can be
replaced; however there will not be a 20-30 second delay for
generator start-up. All repairs should begin by unplugging
and replacing the control module first. However, if the LED is
on and the switch is not working, then the control module is
functioning properly and the switch has other problems, such
as a failed relay or contactor, and the entire switch should be
returned for replacement.
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