APPLICATION
The AT20, AT40, AT72, AT87 and AT88 TRADELINE®
Transformers are step-down transformers used primarily
for powering 24 Vac control systems. They can be used
in any 24 Vac application that does not exceed the
transformer volt-ampere (VA) rating.
The TRADELINE® Transformers will replace all
equivalent Honeywell and competitive transformers with
similar primary voltage requirements, equal or smaller VA
ratings and similar mounting configurations.
Voltage and
Model
Frequency
120 Vac, 50/60 Hz
a
AT20
120 Vac, 50/60 Hz
a
AT40
240 Vac, 50/60 Hz
120 Vac, 50/60 Hz
a
AT72D
240 Vac, 50/60 Hz
a
120 Vac, 50/60 Hz
AT87A
208 Vac, 50/60 Hz
240 Vac, 50/60 Hz
AT88A
120Vac, 50/60 Hz
208/240 Vac, 50/60
Hz
400 Vac, 50/60 Hz
480 Vac, 50/60 Hz
a
Transformer complies with 24 volt NEMA Standard DC-20.
b
Available with female quick-connect terminals on all leadwires.
c
Thermal fuses in primary on 208V/240V models for overload protection.
® U.S. Registered Trademark
Copyright © 2002 Honeywell • All Rights Reserved
AT20, AT40, AT72D, AT87, AT88
Table 1. Transformer Model and Electrical Specifications.
Primary
Wiring Connection
Two 9 in. (229 mm)
leadwires
Three 9 in. (229
mm) leadwires
Two 13 in. (330 mm)
leadwires
Two 12 in. (305 mm)
leadwires
b
AT Transformers
Transformer voltage ratings (primary and secondary),
wiring connection type, and fusing are listed in Table 1.
The transformers are Underwriters Laboratories Inc.
component recognized and Canadian Standards
Association listed and meet NEC Class 2 not wet, Class
3 wet requirements as specified by NEMA Standard
DC-20.
SPECIFICATIONS
Models:
See Table 1.
Secondary
Voltage
Wiring Connection
24 Vac
Two 9 in. (229 mm)
leadwires
Two screw
terminals
24 Vac
Two 12 in. (305
mm) leadwires
INSTALLATION INSTRUCTIONS
Output at
100 Percent
Power
Rating
20 VA
40 VA
50 VA
75 VA
Overload
Protection
Energy
c
Limited
Fuse in
secondary
69-1641EF