Sequence Of Operation Corayvac Modulating Heating Control - Roberts Gorden CORAYVAC Installation Manual

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ROBERTS GORDON CORAYVAC
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6.2.3 Reset to Factory Default Setting
To reset VFD to the factory default setting, press the
Up + Down +Stop buttons simultaneously for 5 sec-
onds. The display will read P-DEF. Press Stop button
to clear screen. Press and hold OK. Reprogram the
parameter according to the instructed recommended
settings.
6.3 Sequence of Operation CORAYVAC
Modulating Heating Control
(CORAYVAC ® System (Modulating))
1. On a call for heat from zone sensor, controller will
verify that vacuum pump air pressure switch is open.
If switch is open, VFD 'Run' command will be issued
to start vacuum pump, vacuum pump LED on control
panel will be lit, and vacuum pump will start immedi-
ately at 100% speed. If controller verifies that vacuum
pump air pressure switch is closed during initial start,
a fault alarm will be activated, and the system will not
start. OPTION: If outside air blower is installed,
blower will start when VFD 'Run' command is issued.
2. After a short run period, vacuum pressure switch
will close, zone LED on control panel will be lit and a
signal is sent to start all burners in the zone to begin
ignition sequence.
3. Burner ignition module will provide a pre-purge of
approximately 45 seconds prior to ignition. After pre-
purge, gas valve will open, and flame is established.
If flame is detected by burner flame sensor, burner
gas valves remain open. If flame is not established,
burner ignition sequence will repeat. After three trials,
the burner module will lockout for one hour or until
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M H C C
ODULATING EATING ONTROL
Motor pick-up control fault
Thermistor fault
Data error
Live zero error
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I M
ONTROLLER NSTALLATION ANUAL
• Motor pick-up control
function (for catching
spinning motors)
failed
• Defective thermistor
on heat sink
• Internal memory error • Parameter not stored: restore
• Analog input current
outside range
manual reset.
Note: Burners in zone may not all fire at exact same
time. Ignition of all burners in zone may vary 3 - 5
seconds.
4. Vacuum pump will run at 100% speed for 2 min-
utes from time that initial 'Run' command is issued.
5. Modulation period begins after 2-minute initial run
period. CORAYVAC
compares outdoor air temperature with zone tem-
perature setpoint and will modulate the CORAYVAC
system appropriately to meet zone temperature set-
point.
6. If zone temperature falls X °F (Default = 5 °F)
below desired setpoint, or if zone temperature is not
changed within 1 °F of setpoint within 30 minutes of
heat cycle, 100% heat request issued.
7. When the call for heat is satisfied, burners shut off,
zone LED light on control panel turns off.
8. The pump will continue operation at 100% speed
for a post-purge period of 2 minutes.
9. After the post-purge period, VFD will drop 'Run'
command and vacuum pump and vacuum pump
LED simultaneously turn off.
OPTION: If outside air blower is installed, blower will
turn off after post purge period.
• The motor pick-up control func-
tion did not determine the
motor speed.
• Please contact Roberts-Gordon
or your ROBERTS GORDON
independent distributor.
default settings.
• If the problem occurs again,
please contact Roberts-Gor-
don or your ROBERTS GOR-
®
DON independent distributor.
• Make sure that the input current
falls within the range defined in
parameter P-16.
® Modulating Heating Control
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