LiftMaster BG770 Industrial-Duty Single Arm Barrier Gate Operator - Manual (Page 14)

T R O U B L E S H O O T I N G
When troubleshooting, one of the first things to do is try to isolate
the problem area. The four (4) main areas to check out are:
• Power
• Accessories
• Operator’s Primary Voltage
• Operator’s Low Voltage
POWER
Always use extreme caution! Some possible symptoms of power
problems include:
• The obvious one is - the operator will not run.
• The operator runs slow.
• Circuit breakers or fuses keep tripping.
• Motor overload keeps tripping.
• Operator starts but then stops.
Using a volt-ohmmeter, take a voltage reading at the control
transformer’s primary terminals. You should get a reading as
follows:
If you get a reading that does not fall into the minimum/maximum
area, then check out your main power supply. Also, make sure
that the operator was ordered with the proper voltage and phase.
Another item to check is the wire run from the power supply to
the operator. Double check the gauge of the wire versus the
distance.
If the voltage reading is okay from 1A, then take the same voltage
reading with the operator running. If voltage drops below the
minimum with this reading, then there could be an excessive
current draw somewhere, or a wire AWG is too small.
In some cases, power drops can occur at only specific times
during the day or night. This can be caused by increased power
demands in a general area at a specific time-particularly areas
undergoing rapid growth.
14
ACCESSORIES
Add-on accessories can create many of the problems that are
credited to the operator. Many applications have more than one
accessory item attached to the operator and some of these items
even draw their power from the operator.
Some of the symptoms that can show up because of accessories:
• The operator will not close.
• The operator will not open. The operator will not run.
• The operator begins to run, then stops or reverses.
Whenever the problem is thought to be an accessory and there
are more than one connected to the operator, always disconnect
one accessory at a time and then test the system. This will
hopefully isolate which item is causing the problem.
If an accessory item is being used as an access control device
(used to open or close), falls in the closed position or sends out a
continuous signal. The operator will hold the gate in one position
until the signal from the accessory is removed.
In some applications, the gate may begin to move then either stop
or stop and reverse within a couple of seconds. This can be
caused by an external obstruction device that has failed.
If there are many accessories attached to and powered by the
operator, there may be too much current draw for the operator’s
control transformer. This operator can only supply approximately
2 amps @ 24Vac. Double check all accessories for their current
requirements.
Nominal Voltage Minimum Maximum
120V 108 132
230V 207 253
460V 414 506