White Rodgers 50A55-743 Drop-In Direct Replacement Furnace Control ユーザーズマニュアル

2

  Input Voltage: 25 VAC 50/60 Hz

 Max. Input Current @ 25 VAC: 0.45 amp

    Relay Load Ratings:

Valve Relay:  1.5 amp @ 25 VAC 50/60 Hz 0.6 pf

Ignitor Relay:  6.0 amp @ 120 VAC 50/60 Hz

 (resistive)

Inducer Relay:  2.2 FLA–3.5 LRA @ 120 VAC

Circulator Relay: 14.5 FLA–25.0 LRA @ 120 VAC

Minimum current to insure flame detection: 1 µa DC*

Maximum current for non-detection: 0.1 µa DC*

Maximum allowable leakage resistance: 100 M ohms

*Measured with a DC microammeter in the flame probe lead
OPERATING TEMPERATURE RANGE:

  -40° to 175°F (-40° to 80°C)
HUMIDITY RANGE:

  5% to 93% relative humidity (non-condensing)
MOUNTING:

  Surface mount multipoise
Timing Specs: (@ 60 Hz**)

 

Flame Establishing Time: 

0.8 sec

Flame Failure Response Time: 

2.0 sec

**At 50 Hz, all timing specifications should be increased 

by 20%

Gases Approved: Natural, Manufactured, Mixed, Liqui-

fied Petroleum, and LP Gas Air Mixtures are all approved 

for use.

Pre-Purge

15

Initial Ignitor Warm-up
(1

st

 64 attempts)

7

Minimum Ignitor Warm-up

5

Maximum Ignitor Warm-up

9

Ignition Activation Period

2

Trial for Ignition Period

4

Retries

2 times

Valve Sequence Period

12

Interpurge

30

Post-Purge

15

Lockout Time

300

Heat Delay-To-Fan-On

30

Heat Delay-To-Fan-Off*

90/120/150/180

Cool Delay-To-Fan-On

5

Cool Delay-To-Fan-Off

45

Auto Reset

60 minutes

Humidifier

Yes

Electronic Air Cleaner

Yes

*These times will vary depending on option switch 

position. See OPERATION section for further 
information

All wiring should be installed according to local and na-

tional electrical codes and ordinances.
The control must be secured to an area that will experience 

a minimum of vibration and remain below the maximum 

ambient temperature rating of 175°F. The control is ap-

proved for minimum ambient temperatures of -40°F.
Any orientation is acceptable.
Refer to the wiring diagram and wiring table when connect-

ing the 50A55 control to other components of the system.
UL approved, 105°C rated 18 gauge, stranded, 

2/64”

 thick 

insulation wire is recommended for all low voltage safety 

circuit connections. Refer to 50A55 specification sheet for 

recommended terminals to mate with those on the control.
UL approved 105°C rated 16 gauge min., stranded, 

4/64”

 

thick insulation wire is recommended for all line voltage 

connections. Refer to 50A55 specification sheet for rec-

ommended terminals to mate with those on the control.
After installation or replacement, follow appliance manu-

facturer’s recommended installation or service instructions 

to ensure proper operation.
The 50A55 has only one serviceable part–an automotive 

type fuse, which protects the low voltage transformer 

from damage if its output is short-circuited. If the fuse 

has opened up, remove whatever caused the short circuit 

and replace the fuse with only a 3 Amp automotive type 

fuse. If the fuse is not the cause of the control’s problem, 

replace the entire 50A55 control. There are no other user 

serviceable parts.