Checking Auxiliary Limit Control - Goodman ACVC96 BA Series Service And Troubleshooting

SERVICING
PRIMARY LIMIT
CONTROL
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2
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Primary Limit Control Location
(90% Upflow Furnace Shown, Counterflow Similar)
The following drawing illustrates the style of limit switches
used on the 90% furnaces.
FRONT VIEW
Primary Limit Control Style
(90% Furnaces)
HIGH VOLTAGE
D ALL
ISCONNECT POWER BEFORE SERVICING OR
CHANGING ANY ELECTRICAL WIRING.
F
SOURCES MAY BE PRESENT. AILURE TO DO SO MAY CAUSE
PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
1. Remove burner compartment door to gain access to
the primary limit.
2. Remove low voltage wires at limit control terminals.
3. With an ohmmeter, test between these two terminals
as shown in the following drawing. The ohmmeter
should read continuous unless heat exchanger tem-
perature is above limit control setting. If not as above,
replace the control.
48
*
*
ENCLOSED DISK
SIDE VIEW
WARNING
M
ULTIPLE POWER
Testing Primary Limit Control
(90% Furnaces)
4. After completing check and/or replacement of primary
limit control, reinstall burner compartment door.
5. Turn on electrical power and verify proper unit operation.
To aid in identifying these controls, refer to the Primary
Limit Charts in furnace Technical Manual for part number,
temperature setting and color(s) code.

CHECKING AUXILIARY LIMIT CONTROL

The auxiliary limit control is designed to prevent furnace
operation in case of main blower failure in horizontal or
counterflow installations. It may also open if the power supply
is interrupted while the furnace is firing.
The auxiliary limit control is suitable for both horizontal
right and horizontal left installations. Regardless of airflow
direction, it does not need to be relocated. The (2) two auxiliary
limits are located on the blower housing (one on each side),
as shown in the following illustration.
AUXILIARY LIMIT
CONTROL
BLOWER HOUSING
Auxiliary Limit Control Location
(Select 90% / 95% Furnaces)

COLOR
IDENTIFYING
TAB
LIMIT
AUXILIARY LIMIT
CONTROL