Heat Wise SU-2A Manual page 8

These gas burners are manufactured for use with 120 volt, 60 cycle, single-phase electric current. The installation must comply and be grounded in accordance with
the National Board of Fire Underwriters and National Electric Code ANSI/NFPA No. 70-1987 (or the latest addition). All applicable local codes should be followed
as well.
Installation wiring should be wired through each limit control or interlock, while operating controls (like the thermostat) should be treated as 24-Volt wiring. The
burner has its own 24 Volt AC power supply. Do not add a 24 Volt AC transformer for the burner wiring. Do not use the 24 Volt transformer found on the burner to
power other items in the heating system, such spill switches, etc. The power supply must have a 15-amp circuit breaker or fuse with a service switch located not more
than 3 feet from the burner. Follow the wiring diagram provided below:
Fig. 4 Wiring Diagram for 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.
7. To restart, power should be interrupted for five minutes. Turn on the power to start this sequence again.
ELECTRIC WIRING
Fig. 5 Wiring Diagram for Optional Motor-Off Delay
SEQUENCE OF OPERATIONS: Honeywell S89F
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