– 8 –
Setting Main Flame
Install manometer at test port on the last tee of the
burner manifold or modulating valve.
Slowly open all manual gas shut-off valves.
Restart unit. After main gas valves open and burner
lights check gas lines for leaks.
Adjust high gas pressure reading (from manometer)
to match firing rate shown on unit nameplate.
Adjust the high fire setting according to the Maxitrol
Valve Adjustment instructions in Section IX. The high
fire setting must not exceed the pressure stated on
the rating plate.
Main flame is now set. Recheck the microamp signal
on the ignition control throughout the full burner input
range. Re-check low fire setting. Cycle unit 2 or 3
times to insure good ignition.
Safety Controls Check All
A. Flame Safeguard (piloted systems only) – Close
last manual gas valve before main burner. Operate
unit in Heat mode. After pilot flame has been estab-
lished, close manual pilot gas valve. The flame safe-
guard must trip out within 15 seconds.
B. Ignition Control (pilotless system only) – Operate
unit in Heat mode. After flame has been established,
close last manual gas valve before main burner. The
ignition control must trip out within 15 seconds. Reset
the ignition control by turning the HEAT switch to the
OFF position.
C. Gas Pressure Switches – The low pressure switch
will trip out and must be reset before resuming opera-
tion when the inlet gas valve is turned off during
operation. The high pressure switch may be checked
out by reducing the setting of its trip point to unit
operating pressure. It should then trip out and shut off
the burner. Return the adjustment to its original setting
and reset to resume operation. When checking
operation of gas pressure switches on systems without
pilot the heat switch will have to be turned off for
approximately five seconds to reset the ignition
control.
D. Air Pressure Switches – The high air pressure
switch is checked by removing the sensing tube from
the entering air side of the burner. Switch operation
will shut off the burner. Recycle is automatic when the
sensing tube is replaced. The low air pressure switch
is checked by removing the sensing tube from the
leaving air side of the burner. Switch operation will
shut off the burner. Recycle is automatic when the
sensing tube is replaced. When checking operation of
air pressure switches on systems without pilot the heat
switch will have to be turned off for approximately five
seconds to reset the ignition control.
E. Adjustable temperature and limit Controls – The
limit controls are checked by adjusting control settings
to a lower temperature setting while the unit is operat-
ing on high fire and observing cutoff. The controls
should be reset to settings shown below:
Suggested Control Settings
TC-01 Room Thermostat ........... Customer Discretion
RE-26 High Limit Discharge Ductstat .................. 95°F
TC-03 On-Off Inlet Ductstat ................................ 65°F
RE-26 Low Limit Discharge Ductstat................... 55°F
TC-08 Freeze Thermostat ................................... 45°F
TC-09 Night Set Back Room ...... Customer Discretion
TC-52 Remote Temperature
Selector ........................... Customer Discretion
PS-04 Low Gas Pressure Switch ................ 1.0" W.C.
PS-07 High Gas Pressure Switch ............. See Below
PS-12
Clogged Filter Switch.......... Adjust to field condition
PS-13
Building Pressure Switch .... Adjust to field condition
FL-02
High Temperature Limit (Manual) ..................185° F
Note: Set high gas pressure setting 125%. above burner
firing rate.
SECTION VI - UNIT SHUTDOWN
A. Extended Shutdown —
1. Set the Heat-On-Off switch to the Off position for
30 seconds, then turn the Fan-On-Off switch to Off
position.
2. Close all manual gas valves.
3. Open the main electrical disconnect switch.
B. Emergency Shutdown ONLY —
1. Open the main electrical disconnect switch.
2. Close the main manual gas valve.
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