Checking Gas Valve; Checking Hot Surface Ignitor; Capacitance Test; Checking White-Rodgers 50A50 Or 50A51 - Amana GUIA070A30 Service Instructions Manual

c. Open - no reading - replace. Reverse leads.
Check again no reading - replace.
d. Reverse leads and recheck.
S-10B Capacitance Test
Volt / Ohm
Meter
AMMETER
Testing Capacitance
With power On (and Door Interlock Switch closed):
WARNING
LINE VOLTAGE NOW PRESENT.
Using a hookup as shown above, take the amperage and
voltage readings and use them in the formula:
Capacitance (MFD)= 2650 x Amperage/Voltage
4. After completing check and/or replacement of capaci-
tor, reinstall blower compartment door.
5. Turn on electrical power and verify proper unit operation.
S-11 CHECKING GAS VALVE (Redundant)
A combination redundant operator type gas valve which pro-
vides all manual and automatic control functions required for
gas fired heating equipment is used.
The valve provides control of main burner gas flow, pressure
regulation, and 100 percent safety shut-off.
WARNING
Disconnect Electrical Power Supply:
1. Remove wire connections from gas valve terminals.
2. Using an ohmmeter, test across the gas valve coil termi-
nals, both the redundant and the main valve.
3. Should read approximately 130 Ohms for the Robert-
shaw main valve operator coils, 100 Ohms for Honeywell
and 100 Ohms for White-Rodgers. The redundant coil
will vary somewhat as well.
SERVICING
4. Reverse leads Some redundant coils have (dividers) di-
odes.
If not as above, replace the entire valve.
S-12 CHECKING HOT SURFACE IGNITOR
A silicone carbide restrictive element ignitor is used for igni-
tion. The normal operating temperature is approximately
2550°F.
Disconnect Electrical Power Supply:
1. Remove burner compartment door to gain access to hot
15 AMP FUSE
surface igniter.
2. Ignitor cool - approximately 70 - 75°F.
3. Disconnect the ignitor from the Ignition Control Module
and line voltage terminal board.
4. Using an ohmmeter measure the resistance of the igni-
tor - should read between 50 to 200 ohms.
5. Reconnect ignitor.
LINE VOLTAGE NOW PRESENT.
6. Place unit in heating cycle, measure current draw of ig-
nitor during preheat cycle. Should read approximately 4
to 5 amps.
7. After check and/or replacement of hot surface igniter,
reinstall burner compartment door and verify proper unit
operation.
S-13 CHECKING WHITE-RODGERS 50A50 OR
Note: Failure to earth ground the furnace, reversing the neu-
tral and hot wire connection to the line (polarity), or a high
resistance connection in the neutral line may cause the
control to lockout due to failure to sense flame.
To avoid the risk of electrical shock, wiring to the unit
must be properly polarized and grounded. Disconnect
power before performing service listed below.
The ground wire must run from the furnace all the way back
to the electrical panel. Proper grounding can be confirmed
by disconnecting the electrical power and measuring resis-
tance between the neutral (white) connection and the burner
closest to the flame sensor. Resistance should be less than
10 ohms.
WARNING
WARNING
50A51 AND HEATCRAFT HSI 1-1A OR HSI-
2 INTEGRATED IGNITION CONTROL
MODULE
CAUTION
81
Rev. 2