Universal Cross Reference
50A55-843 Universal Cross Reference Chart
See other side for 50A50 replacement Cross Reference
Type Number
50A55-120 50A55-143 50A55-285 50A55-286 50A55-288 50A55-438
50A55-474,
-571
50A55-843
Pre-Purge 15 30 0 0 0 0 0
30
Trial for Ignition 4 4 4 7 4 4 4
4
Ignition Activation
Period
1 4 4 4 1 3 1 1
Retries 4 times 4 times 2 times 2 times 2 times 2 times 2 times
2 times
Valve Sequence
Period
12 20 12 21 12 12 12 12
Interpurge 15 60 60 15 60 60 60
60
Post-Purge 5 5 15 15 15 5 5
15
Lockout Time 150 678 272 272 300 269 300
300
Heat
Delay-to-Fan-On
45
15, 30,
45, 60
30 30
30
45
45
30, 45
Heat
Delay-to-Fan-Off
60, 90,
120, 180
60, 90,
120, 180
60, 90,
120, 180
60, 90,
120, 180
60, 90,
120, 180
60, 90,
120, 180
60, 100,
140, 180
60, 90,
120, 180
Cool
Delay-to-Fan-On
0 0 0 0 5 2 2 5
Cool
Delay-to-Fan-Off
0 45 45 45 45 0, 80 0,,80 45, 90
Air Cleaner
terminal
Yes Yes Yes Yes Yes Yes Yes Yes
Humidifier
terminal
Yes Yes Yes Yes Yes Yes Yes Yes
Replaces
*
All times are in seconds
*The Universal 50A55-843 control will replace all 50A50 and 50A55 models
1
Part No. 37-6376A
0204