White Rodgers 50T35-743 - Manual (Page 2)

2
SPECIFICATIONS
ELECTRICAL RATINGS [@ 77°F (25°C)]:
Input Voltage: 25 VAC 60 Hz
Max. Input Current @ 25 VAC:
0.5 amp + Main Value Load
Relay Load Ratings:
Valve Relay: 1.5 amp @ 24 VAC 60 Hz 0.6 pf
Ignitor Relay: 5.0 amp @ 120 VAC 60 Hz
(resistive)
Circulator Relay: 11 FLA–26.0 LRA @ 120 VAC
Humidifier Load Rating: 0.5A @ 24 VAC
1.0A @ 120 VAC
Electronic Air Cleaner Load Rating: 1A @ 120 VAC
Flame Current Requirements:
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:
maximum
Flame Establishing Time: 0.8 sec
Flame Failure Response Time: 2.0 sec
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)
Timing Specification Description 50T35-743
Pre-Purge Initial delay between thermostat contact closure and trial for ignition. 15
Initial Ignitor Warm-Up Duration of ignitor warm-up time on the first 64 attempts. 15
Retry Ignitor Warm-Up Duration of ignitor warm-up time if the control retries. 20
Ignition Activation Period The period of time between energizing the main gas valve and deactivation of 5
the ignition means prior to the lockout time.
Trial for Ignition Period during which the valve and ignition source is activated, attempting to 7
ignite gas at the burner.
Retries Additional ignition attempts if the original ignition attempt is unsuccessful. 2 times
Valve Sequence Period Valve sequence period is the cumulative total amount of time that the gas valve 12
is energized before entering lockout.
Inter-Purge Period between trials for ignition when both the gas valve and ignition source 30
are deactivated to allow unburned gas to escape before the next trial.
Post-Purge After all ignition cycles are complete, the control will enter post-purge. The 25/29
combustion fan will remain on to allow unburned gas to escape. After post-purge (90+ option)
is complete, the combustion fan will turn off.
Lockout Time The period of time between initiation of gas flow and the action to shut off the gas 300
flow in the event of failure to establish proof of the supervised ignition source or
the supervised main burner flame. Reinitiating the lighting sequence requires a
manual operation if ignition is required before Auto reset.
Heat Delay to Fan On Timing to allow the heat to build up in the plenum before turning on the fan. 30
Heat Delay to Fan Off* Timing to allow the fan to run after the call for heat ends. This allows residual heat 90/120/150
to be removed from the heat exchanger and distributed to the conditioned space.
Cool Delay to Fan On Timing to allow the cooling coils to cool off before turning on the fan. 5
Cool Delay to Fan Off Timing to allow the fan to run after the call for cool ends. This allows residual 60
cooling capacity to be removed from the cooling coils and distributed to the
conditioned space.
Auto Reset If shutoff occurs, the control delays for a specific recycle delay period before 60 minutes
beginning another trial for ignition (models with retries only).
* These times will vary depending on option switch position. See INSTALLATION section for further information.