Heat Wise SU-3, Руководство пользователя

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13
SEQUENCE OF OPERATIONS
Honeywell S89F
1. Limits close.
2. Blower motor starts as the 24 Volt transformer powers the
airflow switch.
3. Power from the airflow switch to the S89F control initiates 34
second pre-purge.
4. At the end of the pre-purge, the spark is energized for 4 seconds.
At the same time, the 24 Volt transformer powers the gas valve,
allowing the fuel to flow.
5. Within 4 seconds, the flame should be established and proved.
The spark will shut off and the control will hold power to the
gas valve until the limits open and the burner stops firing.
6. If the flame is not established, the blower motor continuously
runs.
To restart, power should be interrupted for five minutes. Then turn on
the power to start this sequence again.
Optional Valve-on Delay/Motor-off Delay control
*Below 400,000 BTU ONLY *
Not recommended for Propane (LP) applications
SEQUENCE OF OPERATIONS: Fenwal 2466H 036-111
1. All limits are closed and 120-volt power is on for the burner.
2. T-T terminals are closed (24-volt power carrying lines; do not power this.) Sometimes,
T-T terminals are jumped with a wire nut for burners
not set for motor-off delay.
3. Burner motor starts and pre-purge begins
4. Burner housing pressurizes and proves air flow - contacts closed. {Note: if the
contacts are closed before the motor starts, blower motor runs continuously.
Diagnostic light flashes once every 3 seconds.}
5. At the end of pre-purge, ignition spark starts (audible sound) and the redundant gas
valve opens for 4 seconds. (Trial for ignition)
6. Within 4 seconds, gas flame is established and the flame rod carries current to prove
the flame {Note: a minimum of 0.7 micro amps are required; 5 micro amps is not
uncommon.}
7. Flame remains till operating limit is open. If T-T is used to fire the burner (field wired
for post-purge), the burner will go into post-purge once the thermostat is satisfied (T-T
open). These burners have 60 seconds post purge.
8. If the flame is not established, the control will attempt ignition two more times before
locking out for 60 minutes. The control will then attempt to re-establish the flame
every 60 minutes. To reset the control, interrupt power for five minutes to start the
sequence again.
Fig. 6 Honeywell S89F control Fig. 7 Fenwal 2466H