Samlexpower STS-30 Owner's Manual - page 12
12
TROUBLESHOOTING
4
Low voltage
Low voltage is harmful to most appliances. Relay based transfer switches are also affected by low
voltage; if the voltage level drops lower than the holding voltage of the coil, the relay contacts will
“chatter”. Sustained contact chattering may cause damage.
General low voltage
Low voltage can be caused by low voltage conditions such as in an RV park with inadequate
wiring for crowded camper conditions where everyone’s electricity suffers (brownout). In this case,
a voltmeter will be helpful and will show a low voltage reading from the park receptacle, 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 specifi c situations such as an additional cord which is too
long and too small for the load. Do not attempt to extend the RV power cord 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
during inrush current situations such as an air conditioner start-up.
Time Delay for Generator
As already explained earlier, once a generator is started, it should not be loaded immediately. The
time delay is necessary during generator start-up so that the generator does not have to start under
load; the delay is not necessary for electric utility power / Shore Power Cord or inverter. Therefore,
in transfer switch operation where the Transfer Switch is controlling an AC source other than a
generator, the time delay should be disabled and DIP Switch SW1 should be set to (ON) position. This
will allow instantaneous switching.
Another time for disabling the delay is during diagnostic and troubleshooting efforts; if disabling
the delay causes the switch to work when it otherwise won’t, then the time delay circuit has
malfunctioned and the control board PCB1 will be required to be replaced. To disable the time delay,
the DIP Switch SW1 should be set to (ON) position. When time delay is disabled, the transfer will be
instantaneous.