Modine Manufacturing BV 100, Wiring Diagrams

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C -1
SUMMER/WINTER SWITCH WIRING - MODELS PV/BV
Robertshaw
CM260 T-Stat
w/ Subbase
System
Auto
Auto
Off
On
Fan
Before proceeding with wiring the accessories described, make
sure the unit has been installed, vented, piped, and wired
according to the Installation/Service Manual and Standard Wiring
Diagram furnished with this unit heater.
T1
C
V
F
G
To Thermostat
TD Relay
Terminals In Unit
J-Box
Terminal
Board
On J-Box
To Combination
Gas Control or
Ignition Control
T2
2
4
BK
Summer/
Winter Switch
Blue
or
Red
Figure 1
Typical Wiring – Summer/Winter Switch (Modine # 78727)
(24v Thermostat, 115v or 200/230v Summer/Winter Switch)
T1
C
V
F
G
To thermostat
Terminal
Board
On J-Box
To Combination
Gas Control or
Ignition Control
Relay
T2
2 4
Summer/Winter Switch
Relay By Others
(24v Relay Coil,
Line Volt Contacts)
TD Relay Terminals
In J-Box
Figure 2
Typical Wiring – Summer/Winter Switch (Modine # 78727)
(24v Thermostat, 24v Summer/Winter Switch)
T1
C
V
F
G
Terminal
Board
On J-Box
To Combination
Gas Control or
Ignition Control
Wire to Hot
Lead of Power
Exhauster
Motor
TD Relay Terminal
In J-Box
Relay By Others
(24v Relay Coil,
Line Volt Contact)
T2
Figure 3
Alternate Wiring Using Robertshaw CM260
Thermostat w/SB-3A-1 Subbase
(25v Thermostat and Subbase)
(Modine #79187 and #78785 respectively)
3
Relay
W
G
R
CAUTION
Turn off al power to gas to unit before wiring. Failure to wire
this unit according to this wiring diagram may result in injury
to the installer or user. For deviations, contact factory.
!!
1. Turn off gas and power supply to unit.
2. Determine which method of summer/winter control is desired; Figure 1, 2
or 3.
3. Wire unit according to the method selected. NOTE: If the method selected
is as described in Figure 3, the factory supplied buss bar between
terminals “T2” and “F” must be removed prior to wiring in thermostat and
subbase.
4. Check wiring using the Check-Out Procedure below.
Check-Out Procedure
With the power and gas supply turned off, set the thermostat to its lowest
setting and place the summer/winter switch to the winter position. After making
these adjustments proceed as follows:
1.
Turn on gas and power supply to the unit. Nothing should happen.
2. Place the summer/winter switch in the summer position. The fan motor
should start, except when wired as shown in Figure 3. In that case, after a
delay of approximately 30 seconds, the fan motor should start.
3. While the summer/winter switch is still in the summer position, and with
the fan motor running, turn the thermostat up to call for heat. The main
burner should now fire. Allow burner to fire for 1 to 2 minutes.
4. Turn the thermostat down again. The main burner should shut off and the
fan motor should continue to run. During this step, allow the fan to run at
least 1-1/2 minutes to make sure it will continue running. Modine units are
equipped with a time delay relay and the motor will run approximately 1 to
1-1/2 minutes after the time delay relay has been de-energized.
5. After insuring that the fan motor will continue to run in the summer
position, and with the thermostat set to its lowest setting, place the
summer/winter switch in the winter position and wait for the time delay
relay to turn the fan motor off.
6. After the fan motor has stopped, and with the summer/winter switch in the
winter position, turn the thermostat up to call for heat. The main burner
should fire and after a delay of approximately 30 seconds, the fan motor
should run.
If the above sequence of operation does not occur, recheck all wiring until the
necessary correction to the wiring is found and corrected. Set the thermostat
to the desired set point and place summer/winter switch in desired position.
Unit is now ready for use.