White Rodgers 50T35-743 User Manual

2
SPECIFICATIONS
ELECTRICAL RATINGS [@ 77°F (25°C)]:
Input Voltage: 25 VAC 60 Hz
 Max.InputCurrent@25VAC:0.5 amp + MV 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
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Specications
(All times are in seconds, unless noted otherwise)
TimingSpecication 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 the ignition means prior to the lockout time.
5
Trial for Ignition Period during which the valve and ignition source is activated, attempting
to ignite gas at the burner.
7
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 is energized before entering lockout.
12
Inter-Purge Period between trials for ignition when both the gas valve and ignition
source are deactivated to allow unburned gas to escape before the next
trial
30
Post-Purge After all ignition cycles are complete, the control will enter post-purge.
The combustion fan will remain on to allow unburned gas to escape. After
post-purge is complete, the combustion fan will turn off.
25/29
(90+ option)
Lockout Time The period of time between initiation of gas flow and the action to shut
off the gas 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.
300
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 to be removed from the heat exchanger and distributed to
the conditioned space.
90/120/150
Cool Delay to Fan On Timing to allow the cooling coil 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 cooling capacity to be removed from the cooling coils and
distributed to the conditioned space.
60
Auto Reset If shutoff occurs, the control delays for a specific recycle delay period
before beginning another trial for ignition (models with retries only).
60 minutes
*These times will vary depending on option switch position. See INSTALLATION section for further information.

White Rodgers 50T35-743 Specifications

General

Brand	White Rodgers
Model	50T35-743
Category	Control Unit
Language	English