WIRING
1. Disconnect power supply before installing
transformer. All wiring must comply with local
electrical codes and ordinances. Tape all unused
exposed leadwires separately.
2. Connect primary leadwires to line voltage power
supply. See Fig. 23 through 25.
3. Connect transformer secondary leadwires to 24
Vac control system.
COMMON
WHITE (120V) OR ORANGE (240V)
1
SECONDARY CONNECTIONS ARE BLUE AND YELLOW
LEADWIRES.
2
BLACK IS COMMON WITH RESPECT TO THE TRANSFORMER
WINDING ONLY AND NOT THE EXTERNAL CIRCUIT.
Fig. 10. AT20/AT40 Transformer schematic.
208 VAC
240 VAC
1
SECONDARY CONNECTIONS ARE SCREW TERMINALS.
2
BLACK IS COMMON WITH RESPECT TO THE TRANSFORMER
WINDING AND NOT THE EXTERNAL CIRCUIT.
Fig. 11. AT72D, AT87A Transformer schematic.
Automation and Control Solutions
Honeywell
1985 Douglas Drive North
Golden Valley, MN 55422
69-1641EF
G.R. 09-02
2
BLACK
1
24 VAC
M20660
2
BLACK
120 VAC
WHITE
RED
ORANGE
Honeywell Limited-Honeywell Limitée
35 Dynamic Drive
Scarborough, Ontario
M1V 4Z9
COMMON
1
SECONDARY CONNECTIONS ARE BLUE AND YELLOW
LEADWIRES.
2
BLACK IS COMMON WITH RESPECT TO THE TRANSFORMER
WINDING ONLY AND NOT THE EXTERNAL CIRCUIT.
Fig. 12. AT88 Transformer schematic.
CHECKOUT
After installation is complete, turn on power supply.
Placed controlled equipment into operation and observe
through at least one complete cycle. Make sure it
functions as intended.
1
24 VAC
M18321
Printed in China
2
BLACK
208 VAC
RED
240 VAC
ORANGE
www.honeywell.com
1
24 VAC
M20661