Model La400U - Chamberlain LA500U Troubleshooting Manual

MODEL LA400U

SYMPTOM: Operator does not have power.
(Back of Outlet Housing)
Outlet
Outlet
Incoming Power
1 Check the
incoming power.*
Check breaker first, then
check wiring coming
into operator.
The reading should
be 120 Vac.
POWER
OUTLET HOUSING
Incoming Power
J15 Plug
Red
Battery
12V 7AH
Battery
Black
12V 7AH
Check the batteries.*
3
Check the battery connections. Make sure two 7AH batteries OR two 33AH
batteries are connected in series. Check the voltage coming from each battery
by disconnecting the battery from the operator. A fully charged battery should
read 12.8 to 13.3 Vdc per battery. If not, replace the batteries.
CONTROL BOX
CONTROL BOARD
CONTROL BOARD
DIAGNOSTICS
Black
Red
23
*
4
Check the control board.*
Try replacing the fuse.
If that does not work, replace
the control board.
2
Check the transformer.*
Check the voltage coming
from the transformer
(red and black wires at the
CHARGER terminals).
The reading should be
34 Vdc (+/- 10%).
If not, replace the transformer.