Advertisement
SEQUENCE OF OPERATION / FLAME
RECOVERY / SAFETY LOCKOUT
Start Up - Heat Mode
When a call for heat is received from the thermostat supplying 24 volts
to TH/W, the control will reset, perform a self check routine, flash the
diagnostic LED once in the first two seconds, and a pre-purge delay
begins. Following the pre-purge period, the pilot gas valve is energized
and sparks commence for the trial for ignition period. The main gas
valve is de-energized until the pilot flame is detected.
When the pilot flame is detected during the trial for ignition, the
sparking process is shutoff immediately and the main gas valve is
energized. The thermostat and pilot burner flame are constantly
monitored to assure the system continues to operate properly.
When the thermostat is satisfied and the demand for heat ends,
the pilot and main valves are de-energized immediately.
Failure to Light - Lockout
SINGLE TRIAL MODEL
Should the pilot burner fail to light or the pilot flame is not detected
during the trial for ignition period, the control will go into lockout.
The valves are de-energized immediately. The LED will indicate
the code for ignition lockout.
MULTI TRIAL MODEL
Should the pilot burner fail to light, or pilot flame is not detected
during the first trial for ignition period, the pilot and main gas
valves are de-energized. The control then goes through an
interpurge delay before another ignition attempt. The control will
attempt two additional ignition trials before going into lockout and
the valve relays will be de-energized immediately. Recovery from
lockout requires a manual reset by either resetting the thermostat
or removing 24 volts for a period of 5 seconds. On models with
automatic reset, if the thermostat is still calling for heat after one hour
the control will automatically reset and attempt to ignite the burner.
FLAME FAILURE- RE-IGNITION MODE
If the established pilot flame signal is lost while the burner is
operating, the control will respond within 1 second by de-energizing
the main gas valve and energizing the HV spark in an attempt to
relight the pilot burner for the programmed TFI period. If the pilot
burner does not light within the TFI, the pilot gas valve is
de-energized immediately and on multi-try models a new TFI
sequence begins. If the pilot burner does not relight, the control
will lockout as previously described in the "Failure to Light - Lockout"
section. Multi-try models will make 2 more attempts to light the
burner. If pilot flame is re-established, normal operation resumes.
FLAME FAILURE- RECYCLE MODE
The option "recycle after loss of flame" may be selected as a
special feature. With this option, upon loss of pilot flame, gas
valves are de-energized and the controller proceeds to interpurge
before attempting to relight the pilot flame. Multi-try models will
allow three tries for ignition including inter-purges. If pilot burner
relights, normal operation resumes, if pilot burner does not relight,
control will go into lockout as described in "failure to light".
Page 2
Series 35-63, 24 VAC Intermittent Pilot Ignition Control
TABLE 1 - FAULT CONDITIONS
LED INDICATION
FAULT MODE
2 Flashe
Pilot flame without call for heat
s
3 Flashes
Igntion Lockout
Steady On
Internal Control Failure
The LED will flash on for 1/4 second, then off for 1/4 second
during a fault condition. The pause between fault codes is
3 seconds.
Internal Control Failure:
If the control detects an error in its software or hardware,
all outputs are turned off and the LED displays a steady
ON condition.
MOUNTING AND WIRING
The Series 35-63 is not position sensitive and can be
mounted vertically or horizontally. The case may be mounted
on any surface with #6 sheet metal screws.
WARNING:
All wiring must be done in accordance with both local
and national electrical code.
WARNING:
The Series 35-63 uses voltages of shock hazard potential.
Wiring and initial operation must be done by a qualified
service technician.
TABLE 2 - WIRING TERMINALS
TERMINAL
DESCRIPTION
TH/W
Thermostat Input
PV1
Pilot Valve Power
MV1
Main Valve Power
V2
Valve Ground
GND
System Ground
S1
Remote Flame Sensor (Optional) 1/4 inch
HV
High Voltage Output
CAUTIONS:
Label all wires prior to disconnection when servicing controls.
Wiring errors can cause improper and dangerous operation.
A functional checkout of a replacement control is recommended.
WARNING:
Operation outside specifications could result in failure of the Fenwal
product and other equipment with injury to people and property
www.fenwalcontrols.com
QUICK CONNECT
1/4 inch
3/16 inch
1/4 inch
3/16 inch
3/16 inch
1/4 inch
1-800-FENWAL-1
Advertisement
