Sequence Of Operations - resideo WV4460E Instructions D'installation

WV4460E POWER VENT WATER HEATER CONTROLS
c. Make sure electrical connections are clean and
tight.
d. Check for cracked ceramic Insulator, which can
cause short to ground, and replace igniter-sen-
sor if necessary.
e. Check the pilot flame. Make sure it is blue,
steady, and envelops 3/8 to 1/2 in. (10 to 13
mm) of the flame rod.
4. After completing step 3, if any conditions in step 2
above recur, then replace the Control.
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 season-
ally should be checked before shutdown and again
before the next use.
Sequence
1 Start-up
2 Flammable Vapor Check
0 Idle
1 Heat demand
2 Open pressure switch
3 Energize draft motor
4 Close Pressure switch
5 Energize pilot and spark igniter
6 De-energize spark igniter
7 Energize main gas valve
8 Wait 3 seconds to stabilize flame
69-1872EF—03
Table 4. WV4460E Sequence of Operation.
Mode
Power Up
Heating Sequence
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 deteriorate
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.
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 pressure switch to insure that it
is open.
The induced draft motor is energized.
The control monitors the pressure switch until it closes.
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).
The main valve is energized (when flame is proved above
the "RUN" level).
Flame and Pressure Switch signals are ignored for 3
seconds after the main valve is energized (Flame
Stabilization Period).
8
Description