White Rodgers 50A55-143 User Manual

Page of 8
2
SPECIFICATIONS
ELECTRICAL RATINGS [@ 77
°
F (25
°
C)]:
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
Flame Current Requirements:
Minimum current to insure flame detection: 1 
µ
a DC*
Maximum current for non-detection: 0.1 
µ
a 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**)
maximum
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, Liquified
Petroleum, and LP Gas Air Mixtures are all approved for
use.
TIMING SPECIFICATIONS
(All times are in seconds, unless noted otherwise)
PRE-PURGE
INITIAL IGNITOR 
WARM-UP (1st 64 
attempts)
MINIMUM IGNITOR 
WARM-UP
MAXIMUM IGNITOR 
WARM-UP
IGNITION ACTIVATION 
PERIOD
TRIAL FOR IGNITION 
PERIOD
RETRIES
VALVE SEQUENCE 
PERIOD
INTERPURGE
POST-PURGE
LOCKOUT TIME
DELAY TO HEAT ON
DELAY TO HEAT OFF
DELAY TO COOL ON
DELAY TO COOL OFF
AUTO RESET
HUMIDIFIER
ELECTRONIC AIR 
CLEANER
30
17
5
21
1
4
2 times
12
60
5
300
15/30/ 
45/60
60/90/ 
120/180
0
90
70 minutes
YES
YES
50A55-143