GeneralAire GA50A20 - Manual (Page 7)

your installer or dealer. To replace filters, perform the
following functions:
1. Turn Air Cleaner power switch OFF.
2. Turn off system fan.
3. Open access door.
4. Remove collecting cells from Air Cleaner.
5. Remove the used carbon filters from Air Cleaner.
6. Put new carbon filters into Air Cleaner. Space filters
evenly across the discharge opening of Air Cleaner.
Never put more than 3 carbon filters in the Air
Cleaner, as this may cause a problem with airflow.
SERVICE
The Air Cleaner when operating normally, with the
fan running, should have both the switch light and the
performance indicator light ON. If the fan is running and
the lights are not on see the Troubleshooting Guide for
probable causes and remedies.
Quick Check (Power Light ON, Performance Light OFF)
1. Make sure the system fan is ON. Remove both
cells.
2. Close the door. If the light is still out, check the
power board for an arc to ground at HV1 or HV2. If
there is a good arc and no performance light then
replace the light. If the light comes on check the
cells for a fault.
3. If there is no arc, test the output voltage of the
transformer. If there is transformer output replace
the power board
4. If there is no transformer output, check for output of
the APS.
5. If there is output from the APS replace the
transformer and retest the power board for an arc.
6. If there is no output from the APS, jumper terminals
3 & 4 on the APS and retest the output. If there is
APS output with the jumper, replace the APS.
7. If there is no output from the APS check the output
voltage from the on/off switch.
8. If there is no voltage from the switch, test the input
to the switch. If there is input replace the switch. If
there is no input to the switch check the interlock
switch and the supply voltage.
Testing For High Voltage At Power Board
With the collecting cells out of the unit, the door on
the unit and the system fan on high speed, turn the Air
Cleaner ON.
With a long shafted screwdriver, with a plastic
handle, short between the grounded side of the power
box and the HV1 terminal of the power board.
If you draw a good spark, there is high voltage from
the power board.
Measuring High Voltage At Power Board
A high voltage meter capable of measuring up to
10,000 VDC is required to test the voltage.
1. The Air Cleaner should be ON with the cells installed,
the door closed and the system fan running. The Air
Cleaner should be on at least 5 minutes to allow
voltage to stabilize. The cells and ionizing wires must
be clean.
2. Remove the cover from power box.
3. Connect the ground of the high voltage meter to an
unpainted surface in the power box.
4. Check terminals HV1 and HV2 on the power board to
determine if voltage is present. See Table 3 for
values..
5. If no voltage is present, remove both cells from the
Air Cleaner and replace door.
a. Check the voltage at HV1 and HV2 again.
b. If voltage is present, the problem is with one of
the cells or the wiring to the copper contacts.
c. With a flashlight, look into the cabinet to check
condition of the copper contacts.
d. If the contacts are not bent, replace one cell and
retest voltage. If cell is OK, test the other cell. If
the problem is with a cell, see Troubleshooting
Guide.
e. If there is no voltage with both cells removed,
check the power board, APS and transformer to
make sure that they are functioning correctly.
6. If there is voltage present, but the performance light
does not come on, replace light.
7. High voltage can be adjusted with high voltage
potentiometer if required. See Table 3.
Replacing A Performance Light
Before replacing the performance light, turn OFF
power to the Air Cleaner at the source.
1. Remove the power box cover.
2. Disconnect the performance light wiring connected to
the LED terminals on the power board. Carefully cut
the wire ties from the wire bundle.
7
WARNING
Electronic Air Cleaners use high voltage (low
amperage). Only trained personnel should perform
service. USE CAUTION! Electric shock can cause injury
or death.
CAUTION
For most troubleshooting the cells should be
removed from the Air Cleaner. A short in one of the
cells will cause the power board to shutdown and the
performance light will stay off. Unless otherwise directed
remove the cells from the unit when testing.
WARNING
When performing LIVE tests in the power box NEVER
touch any parts other then what are mentioned in the
tests. Components carry dangerous voltages and
extreme care must be taken.