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SECTION VI - UNIT SHUTDOWN
A. Extended Shutdown —
1. Disable the heating and cooling for 30 seconds,
then disable the fan.
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.
Safety Controls Check All
A. Ignition Control (RE-02) – Close last manual gas
valve before main burner. Operate unit in Heat mode.
The ignition control must lock out within approximately
15 seconds.
B. High Temperature Limits and Firestats – These limit
controls are not adjustable and are checked at the
factory. Reset the button(s) to be sure they are ready
for operation. Contact factory if these switches fail to
reset.
C. Gas Pressure Switches – The low pressure switch
will trip out and must be reset before resuming op-
eration 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 oper-
ating pressure. It should then trip out and shut off the
burner. Return the adjustment to its original setting and
reset to resume operation.
D. Air Pressure Switches – The high air pressure
switch is checked by removing the sensing tube
from the entering air side of the burner and gently
blow into the switch connection. 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.
Do not adjust air fl ow
switches.
E. Adjustable temperature and limit Controls – The
limit controls are checked by adjusting control
settings to a lower temperature setting while the unit
is operating on high
fi
re and observing cutoff. The
controls should be reset to settings shown below:
Make sure all the safeties and controls are working
properly.
Suggested Control Settings
(Refer to Digital Control System user manual for default settings)
TS-02 Space Temperature Sensor ..... Customer Discretion
KP-01 Keypad/Display Module ........... Customer Discretion
MP-05 Damper Control Potentiometer ... Customer Discretion
MP-15 Unit Enable Potentiometer ....... Customer Discretion
PS-04 Low Gas
Pressure Switch .........................................1.0" W.C.
PS-07 High Gas
Pressure Switch ........ 125% above burner
fi
ring rate
PS-12 Clogged Filter Switch ............Adjust to
fi
eld condition
PT-13 Building Pressure Transducer .. Adjust to
fi
eld condition
FL-02 High Temperature Limit (Manual) ................... 185° F
Cooling is Enabled By The Following:
MDT And MRT Standard:
To enable the
cooling
, rotate the
“Temperature
Setpoint”
knob (MP-15) clockwise to the desired
setpoint below the actual air temperature. The
allowable temperature range is 55
o
to 90
o
F.
MRT-PRO With Smart Room Sensor:
To
enable
the cooling, press the
“Warmer”
or
“Cooler”
button on the face of the remote
MRT-Pro
room sensor
(TS-02)
to the desired room setpoint.
Each push of the button changes the temperature
setpoint by 1
o
F. The setpoint can be changed
a maximum of + 10
o
F from the default of 73
o
F.
Changing the cooling setpoint also changes the
heating setpoint.
MRT Expert or VDT Expert With A BACview (KP-01):
To
enable
the cooling for MRT Expert scroll through
the
“Setpoints”
menu in the BACview and enter the
desired room
Cooling Occupied and Unoccupied
Setpoints
. For VDT Expert enter the desired Cooling
Discharge Air Setpoint.
Energy Savings Mode:
Energy Savings Mode 4 can disable the cooling.
NOTE: The cooling outputs are protected by an
anti-cycle timer which has a 3 minute off/3 minute
on delay. A BACview or PC is required to change
Setpoints. For a more detailed control sequence,
see the Digital Control User Manual.
