Harman Stove Company DVC500-C Manual page 31

DVC 500-C
Firebox Static Pressure
Safety Protocol
The DVC-500 operates with a negative pressure
firebox as a safety feature. The control continu-
ously adjusts the draft motor speed to maintain a
safe firebox negative static.
If the control cannot maintain this negative static
at full draft motor speed, a Three Stage Safety
Protocol is started.
Stage 1
When the safety switch senses a loss of negative
pressure in the firebox for more than 68 seconds
the following happens:
The combustion blower will reduce in speed.
During this cool down period the feeder is allowed
to opreate. If needed the feeder can opreate for
up to 3 minutes.
After 72 minutes, if the safety switch has not
sensed another pressure loss, the unit will
automatically go to the control board setting.
If the safety switch senses a loss of negative
pressure anytime during the STAGE 1 Protocol,
the unit automatically goes to the STAGE 2
Protocol.
Stage 2:
When the safety switch senses a loss of negative
pressure in the firebox for more than 68 sec-
onds, the following happens:
The status light will start to blink ( 2 blinks ).
The combustion blower and feeder motor will shut
off.
These motors will remain off for a 5 minute cool-
2 Blink Status Details:
down period.
After five minutes the unit will restart at a reduced
feed rate ( 30 seconds max.) for 72 minutes.
After 72 minutes, if the safety switch has not
sensed another pressure loss, the unit will
automatically go back up to Stage 1.
The status light will continue to blink (2 blinks)
throughout Stage 1 and Stage 2.
If the safety switch senses a loss of negative
pressure anytime during the Stage 2 Protocol,
the unit automatically goes to the Stage 3
Protocol.
[At any time the 2 blink status can be reset by
disconnecting the power to the unit for a few
seconds.]
Stage 3:
When the safety switch senses a loss of negative
pressure in the firebox for more than 68 sec-
onds, the following happens:
The status light will continue to blink 2 blinks.
The Distribution Blower will be cycling "high" to
"low" as on audible warning.
The Combustion Blower and Feeder Motor will
shut off.
When the unit reaches Stage 3 these motors will
not restart.
The Draft Motor will continue to run but the fire
will go out.
The Stage 3 Protocol generally indicates that
service is necessary.
[At any time the 2 blink status can be reset by
disconnecting the power to the unit for a few
seconds.]
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