Maintenance; Sequence Of Operations - Honeywell WV4262B Installation Instructions Manual

WV4262B POWERED DAMPER WATER HEATER CONTROLS

MAINTENANCE

WARNING
Fire or Explosion Hazard
Can cause severe injury, death, or property
damage.
Do not attempt to take the control apart or
clean it. Improper cleaning or reassembly can
cause gas leakage.
The maintenance program should include regular
checkout of the control as outlined in the Installation
section, and the control system as described in the
appliance manufacturer literature.
Maintenance frequency must be determined
individually for each application. Some considerations
are:
1. Cycling frequency. Appliances that may cycle
3,000 times annually should be checked
monthly.
2. Intermittent use. Appliances that are used sea-
sonally should be checked before shutdown and
again before the next use.
3. Consequence of unexpected shutdown. Where
the cost of an unexpected shutdown would be
high, the system should be checked more often.
4. Dusty, wet, or corrosive environment. Since these
environments can cause the control to deterio-
rate more rapidly, the system should be checked
more often.
The system should be replaced if:
a. It does not perform properly on checkout or
troubleshooting.
b. The control is likely to have operated for
more than 100,000 cycles.
c. The control has been flooded.
Sequence
1 Start-up
2 Flammable Vapor Check
0 Idle
1 Heat demand
2 Check damper end switch
3 Energize damper motor
4 Monitor damper end switch
5 Energize pilot and spark igniter
6 De-energize spark igniter
69-2496—03
Table 4. WV4262B Sequence of Operation.
Mode
Power Up
Heating Sequence
SERVICE
WARNING
Fire or Explosion Hazard
Can cause severe injury, death, or property
damage.
Do not disassemble the water heater control; it
contains no replaceable components.
Attempted disassembly or repair can damage
the control.

Sequence of Operations

1. Follow the sequence of operation as shown
in Table 4.
Upon Power up, the control runs a safe-start check of
RAM, ROM, and I/O with a typical start-up delay of 1-2
seconds.
To insure no outputs are energized if flammable vapors
are present, the control pre-loads a condition indicating
flammable vapors are present. If no vapors are really
present, then the control resumes normal operation with
no perceptible delays. If vapors are present, the control
will immediately perform the flammable vapor lockout.
Normal operation
The control receives a demand for heat (the temperature
is less than set point minus differential).
The control checks the damper end switch to insure the
damper is closed.
The damper motor is energized.
The control monitors the damper end switch until the
damper is open.
The pilot valve and spark igniter are energized (after the
Prepurge time).
The igniter is de-energized (when flame is proved above
the "Igniter Off" level).
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Description