Trane UD1A040A9241A Series Installer's Manual page 16

TWINNING CONNECTION DIAGRAMS
Installer's Guide
TWINNING
These furnaces may be twinned. Twinning requires that two
furnaces with the same configuration, capacity, and airflow
1 STAGE HEAT
ONLY
THERMOSTAT
(WITH FAN SWITCH)
SEE NOTE 3
B/C
OUTDOOR UNIT
(WITH TRANSFORMER)
ISOLATION RELAY
(FIELD SUPPLIED)
SEE NOTE 3
OUTDOOR UNIT
(NO TRANSFORMER)
16
TWINNING CONNECTION DIAGRAM
FOR TWINNING 1 STAGE FURNACES WITH
SINGLE WIRE TWINNING FEATURE
1 STAGE HEATING ONLY THERMOSTAT
FURNACE NO. 1
TWIN
ISOLATION RELAY
(FIELD SUPPLIED)
SEE NOTE 4
R1
B/C
TWINNING CONNECTION DIAGRAM
FOR TWINNING 1 STAGE FURNACES WITH
SINGLE WIRE TWINNING FEATURE
1 STAGE HEAT / 1 STAGE COOL THERMOSTAT
1 STAGE
HEATING / COOLING
THERMOSTAT FURNACE NO. 1
TWIN
SEE NOTE 5
B/C
B/C
must be used. They shall have common returns with equal
pressure drops or ducts with equivalent lengths and sizes.
See Field Wiring Diagrams below for proper hookup.
FURNACE NO. 2
BLOWER OPERATION OF
UNIT NO. 2 IS SYNCRONIZED
WITH UNIT NO. 1 VIA SIGNALS
FROM TWIN CONNECTION.
TWIN
SEE NOTE 4
R1
ISOLATION RELAY
SEE NOTE 4
B/C
From Dwg. 21B341422 Rev. 3
FURNACE NO. 2
BLOWER OPERATION OF
UNIT NO. 2 IS SYNCRONIZED
WITH UNIT NO. 1 VIA SIGNALS
FROM TWIN CONNECTION.
TWIN
SEE NOTE 4
R1
ISOLATION RELAY
R1
B/C
ISOLATION RELAY
(FIELD SUPPLIED)
SEE NOTE 4
SEE NOTE 4
From Dwg. 21B341423 Rev. 2
18-CD19D7-22