51
®
CHECK-RUN SWITCH
The Check-Run switch is located on the underside of the YB
Chassis Module (note drawing on right) and can be used to stop
the control in its firing sequence at any time in the burner
sequence. It is designed to aid in set-up, start-up and check-out of
the burner and its associated interlocks.
Following are the modes of operation:
1.
When power is applied to the control (Ll-L2) and the operat-
ing control circuit is closed (L1-3), the purge period begins
and the firing rate motor is sent to the Hi Purge position. If the Check-Run Switch is moved to
the Check position before the open damper 30 second purge period ends, the control will dis-
play:
The control will hold in this position indefinitely to allow the operator to make interlock switch and
linkage adjustments. To continue in the cycle, move the Check-Run switch to Run to allow the con-
trol to advance.
2.
If the Check-Run switch is moved to the Check position after the open damper purge period, but
before low fire start period ends, the control will display:
The control will hold in this position indefinitely to allow the operator to make interlock switch and
linkage adjustments. To continue the cycle, moving the Check-Run Switch to Run will allow the
control to advance.
3.
During the PTFI period, switching to the Check position will stop the program in the PTFI
period, allowing for pilot and/or scanner alignment adjustments to be made. The control will
display:
It will hold in this position indefinitely as long as the flame signal strength is above the threshold of
10. If it drops below 10 for thirty (30) consecutive seconds, lockout will occur and the message on
the display will read Flame Fail PTFI.
4.
During the MTFI period, switching to the Check position will stop the program in the MTFI
period. At this point it may be useful to inspect the position of the main flame at the burner head.
Depending on where the switch is placed in check and depending on the selection of
PTFI*MTFI TIMING, terminals 5, 6 and 7 could be energized simultaneously. The control will
display:
If the unit is left in Check for longer than 2 minutes, the control will automatically advance to
AUTO.
5.
Switching from run to check during the burner on period will drive the modulator circuit to low
fire (10-12 Closes). This allows for low fire fuel-air adjustments and holding the burner at low
fire. Consult your boiler/burner instructions for low fire hold firing recommendations. The con-
trol will display:
COMMS
COMMS
EXP
EXP
RUN/CHK
RUN/CHK
CHECK
00:24
HIGH FIRE PURGE
CHECK
00:24
LOW FIRE PURGE
CHECK
35
FLAME SIGNAL
CHECK
35
FLAME SIGNAL
CHECK
35
LOW FIRE SIGNAL
