Product Manual
6
Operation
To turn the unit on, simply move the power switch to the ON position. The alarm buzzer will
sound and the Low Input LED will come on briey, and then the green Output ON LED will
illuminate. If you wish to adjust the output voltage, remove the cover plate (secured by 2
screws) to expose the output adjust potentiometer. Reach in with a very small at blade
screwdriver to rotate the potentiometer. Clockwise increases the output voltage, and counter
clockwise decreases it. When you are done, replace the cover plate and securely tighten the
screws.
Troubleshooting
If the red Over-temperature LED and the audible alarm come on, the unit has overheated,
and it will shut down until it cools off sufciently. You may not have allowed sufcient space
around the unit for cooling, or there may be too many devices connected to the output of
the unit. Either reduce the number of devices connected to the unit, or reposition the unit for
better cooling. If necessary, direct a stream of moving air over the heat sink.
If the yellow Low Input LED comes on, the input voltage has dropped below 19 VDC (27
VDC on the -24 version). To keep from completely discharging the batteries, the unit will shut
down until the voltage recovers to 21 VDC (29 VDC on the -24 version). Make sure that the
charging system is operating properly and that the wires connecting the input voltage to the
unit are not corroded or damaged.
If the red Overload LED comes on the output current has exceeded the maximum rating. If
the unit is seriously overloaded, the yellow Low Output LED and the audible alarm will also
come on. The green Output On LED will still be on, but it will be dimmer than normal. Remove
loads as necessary to prevent the Overload LED from coming on.
If the red Overload LED, the Low Output LED and the audible alarm come on, and the
green Output On LED is completely off, the output of the unit has been shorted out, or
there has been an internal failure. Turn the unit off, disconnect all the loads connected to it,
and turn it back on again. If it comes on normally, turn it off again, reconnect one load, and
turn it back on. Continue reconnecting loads until the short circuit condition returns. Turn the
unit off, disconnect the faulty load, and reconnect it only after the fault is found and rectied.
If the condition still exists even after all the loads have been disconnected, the unit is defec-
tive, and must be returned to the factory or an authorized service center for repair.
If the unit will not turn on at all, check the input fuses. If they are blown, replace them with
new ones. If those fuses blow as well or the unit still will not turn on, it is defective, and must
be returned to the factory or an authorized service center for repair.