Johnson Controls TM9T*MP Twinning Instructions, Twinning Operation, Condensate Drain Location

505309-UIM-D-0511

Twinning Instructions

Connect the control wiring as shown in Figure 21.

1.Connect the low voltage wiring from the wall thermostat to the termi- nal strip on the control board of Furnace #1.

2.Connect a wire from the TWIN terminal of Furnace #1 to the TWIN terminal of Furnace #2.

3.Install a separate 24V relay as shown in the diagram below. Use of this relay is required, as it ensures that the transformers of the two furnaces are isolated, thus preventing the possibility of any safety devices being bypassed.

4.Connect the 24V common wires of furnace #1 to the 24V common terminal of furnace #2.

Twinning Operation

Heating - On a call for heat (W signal) from the wall thermostat, both furnaces will start the ignition sequence and the burners on both fur- naces will light. About thirty seconds after the burners light, the blowers on both furnaces will come on in heating speed. When the thermostat is satisfied, the burners will all shut off and, after the selected blower off delay time, both blowers will shut off at the same time. The twinning control ensures that both blowers come on and shut off at the same time.

Cooling - On a call for cooling (Y signal) from the wall thermostat, both furnace blowers will come on at the same time in cooling speed. When the thermostat is satisfied, both blowers will stay on for 60 seconds, then will shut off at the same time.

Continuous Fan - On a thermostat call for continuous fan (G signal), both furnace blowers will come on at the same time in cooling speed and will stay on until the G signal is removed.

FURNACE 1	FURNACE 2
CONTROL BOARD	CONTROL BOARD

The furnace condensate pan is self priming and contains an internal trap to prevent flue gas leaking. Do not install an external condensate trap.

When drain hose routing changes are required (shown in Figures 24- 27), be sure to cap all un-used openings.

If rerouting hoses - excess length should be cut off so that no sagging loops will collect and hold condensate - which will cause the furnace to not operate.

No hose clamps are needed for connecting to the condensate pan.

The furnace, evaporator coil, and humidifier drains may be combined and drained together. The evaporator coil drain may have an exter- nal, field-supplied trap prior to the furnace drain connection to prevent conditioned air leakage. All drain connections (furnace, evaporator coil, or humidifier) must be terminated into an open or vented drain as close to the respective equipment as possible. Regular maintenance is required on condensate drainage system.

Condensate must be disposed of properly. Follow local plumbing

or wastewater codes. The drain line must maintain a 1/4" per foot (20 mm/m) downward slope to the drain.

W
G
C
R	TWIN
Y	ISOLATION
	RELAY

W

G

C

R TWIN Y

If an external vent tee is being installed, then it must have its own condensate trap before it is disposed into an open or vented drain.

This is not to be considered as a second trap as referenced else- where in this document.

TO A/C		W G R Y
	WALL THERMOSTAT

FIGURE 21: Twinning Wiring Diagram

SECTION VII: CONDENSATE PIPING AND FURNACE VENTING CONFIGURATION

CONDENSATE DRAIN LOCATION

As shipped from the factory:

•For all 040, 060, & 080K input furnaces the main drain is plumbed through the casing right-side opening when viewed from the front of the furnace.

•For all 100, 120, & 130K input furnaces the main drain is plumbed through the casing left-side opening when viewed from the front of the furnace.

NOTICE

The Figures 24 - 27 show the condensate drain arrangement for the various possible furnace and vent blower positions.

The condensate hoses must slope downwards at all points.

Open Stand Pipe (Anti-siphon air vent)

5” Min.

Tee

To Open Or

Vented Drain

FIGURE 22: Typical. Condensate drain, vertical installation

16 Johnson Controls Unitary Products