Instructions / Assembly

ManualsBrandsUnbranded ManualsHeating, Ventilation, and Air Conditioning24-Volt Transformer

INSTALLATION INSTRUCTIONS

69-1641EF-01

AT20, AT40, AT72D, AT87, AT88

AT Transformers

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.

Transformer voltage ratings (primary and secondary),

wiring connection type, and fusing are listed in Table

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.

Table 1. Transformer Model and Electrical Specifications.

Transformer complies with 24 volt NEMA Standard DC-20.

Available with female quick-connect terminals on all leadwires.

Thermal fuses in primary on 208V/240V models for overload protection.

Model

Primary Secondary Output at

100 Percent

Power

Rating

Overload

Protection

Voltage and

Frequency

Wiring

Connection Voltage

Wiring

Connection

AT20

120 Vac, 50/60 Hz Two 9 in. (229 mm)

leadwires

24 Vac Two 9 in. (229 mm)

leadwires

20 VA Energy

Limited

AT40

120 Vac, 50/60 Hz 40 VA

240 Vac, 50/60 Hz

AT72D

120 Vac, 50/60 Hz Two screw

terminals

240 Vac, 50/60 Hz Three 9 in. (229

mm) leadwires

AT87A

120 Vac, 50/60 Hz Two 13 in. (330

mm) leadwires

50 VA

208 Vac, 50/60 Hz

240 Vac, 50/60 Hz

AT88A 120Vac, 50/60 Hz Two 12 in. (305

mm) leadwires

24 Vac Two 12 in. (305

mm) leadwires

75 VA Fuse in

secondary

208/240 Vac,

50/60 Hz

400 Vac, 50/60 Hz

480 Vac, 50/60

Summary of content (12 pages)

PAGE 1
AT20, AT40, AT72D, AT87, AT88 AT Transformers INSTALLATION INSTRUCTIONS 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.
PAGE 2
AT20, AT40, AT72D, AT87, AT88 AT TRANSFORMERS INSTALLATION A B C in. mm in. mm in. D mm in. USE SCREWS OR BOLTS THROUGH SLOTS (4) IN MOUNTING FEET E mm in. mm AT40C 2-13/32 61 7/8 22 1-3/4 44 2-3/16 56 2-7/8 73 AT87A 2-13/32 61 1 1-3/4 44 2-1/16 52 3 25 76 When Installing This Product… 1. 2. 3. 4. Read these instructions carefully. Failure to follow them could damage the product or cause a hazardous condition.
PAGE 3
AT20, AT40, AT72D, AT87, AT88 AT TRANSFORMERS Mounting the AT72D Transformer. 4. With the plate in place over the clamp, tighten the screw securely against the rim of the round hold See Fig. 5. Avoid damaging the leadwires with the screwdriver. To mount the plate at the laminations (transformer 3/4 above the mounting plate: Mount the transformer to meet the application. Use one of the methods illustrated. The transformer can be mounted in any position. 1. Foot Mounting. 1. 2. 2.
PAGE 4
AT20, AT40, AT72D, AT87, AT88 AT TRANSFORMERS PLATE MOUNTED AT CLAMP ON END BELL (ALL ABOVE PLATE MOUNTING) MOUNTING PLATE END BELL CLAMP SCREW AND CLAMP SCREW TERMINALS FOR SECONDARY CONNECTIONS LEADWIRES FOR PRIMARY CONNECTIONS M12126 RAISED PORTION OF LARGE CENTER KNOCKOUT Fig. 5. Tighten clamp securely against rim of round hole.
PAGE 5
AT20, AT40, AT72D, AT87, AT88 AT TRANSFORMERS USE SCREWS OR BOLTS THROUGH SLOTS (4) IN MOUNTING FEET LEADWIRES FOR PRIMARY CONNECTIONS SLOT SCREW TERMINALS FOR SECONDARY CONNECTIONS TAB M20855 Fig. 7. Tab on mounting plate fits in slot on transformer mounting foot. TRANSFORMER MOUNTING FOOT (2) PLATE M20659 Fig. 10. Foot mounting of AT87 Transformer. T AN R RT PO ME IM UNT OR F E O M ANS SID TR HER OT Plate Mounting The mounting plate allows the transformer to be mounted on a 4 in. by 4 in.
PAGE 6
AT20, AT40, AT72D, AT87, AT88 AT TRANSFORMERS WIRING 1. 2. 3. Disconnect power supply before installing transformer. All wiring must comply with local electrical codes and ordinances. Tape all unused exposed leadwires separately. Connect primary leadwires to line voltage power supply. See Fig. 11 through 13. Connect transformer secondary leadwires to 24 Vac control system. 2 BLACK 120 VAC WHITE 208 VAC 1 24 VAC RED 240 VAC ORANGE 2 COMMON 1 SECONDARY CONNECTIONS ARE SCREW TERMINALS.
PAGE 7
Transformateurs AT AT20, AT40, AT72D, AT87, AT88 NOTICE D'INSTALLATION APPLICATION Les transformateurs abaisseurs TRADELINE® AT20, AT72, AT87 et AT88 sont utilisés principalement pour alimenter les systèmes de régulation 24 V c.a. Ils peuvent être utilisés dans toutes les applications 24 V c.a. qui ne dépassent pas la valeur nominale en voltampères (VA) du transformateur.
PAGE 8
TRANSFORMATEURS AT AT20, AT40, AT72D, AT87, AT88 INSTALLATION A B C po. mm po. mm D po. mm po. INSÉRER DES VIS OU DES BOULONS DANS LES FENTES (4) DU SOCLE DE MONTAGE E mm po. mm AT40C 2-13/32 61 7/8 22 1-3/4 44 2-3/16 56 2-7/8 73 AT87A 2-13/32 61 1 1-3/4 44 2-1/16 52 3 25 76 Avant d'installer ce produit… 1. 2. 3. 4. Lire les présentes instructions attentivement. Le fait de ne pas les suivre pourrait endommager le produit ou constituer un danger.
PAGE 9
TRANSFORMATEURS AT AT20, AT40, AT72D, AT87, AT88 Montage du transformateur AT72D 1. 2. Monter le transformateur en tenant compte de l'application. Choisir l'une des méthodes illustrées. Le transformateur peut être monté dans n'importe quelle position. 3. 4. Montage sur socle 1. 2. Mettre de côté la plaque de montage. Insérer des vis ou des boulons dans les fentes du socle de montage pour fixer le transformateur sur la surface de montage. 5.
PAGE 10
TRANSFORMATEURS AT AT20, AT40, AT72D, AT87, AT88 1. 2. 3. Utiliser les vis fournies avec la boîte électrique. Insérer les vis dans les bons trous de montage de la plaque et fixer le transformateur et la plaque sur la boîte. Défoncer les ouvertures défonçables correspondant aux trous de montage de la plaque, s'il y a lieu. M12126 Fig. 5. Bien serrer l'étrier sur le rebord du trou rond. PLACER LA PARTIE SURÉLEVÉE DE L'OUVERTURE DÉFONÇABLE VERS SOI, PUIS : 1.
PAGE 11
TRANSFORMATEURS AT AT20, AT40, AT72D, AT87, AT88 TRANSFORMATEUR INSÉRER DES VIS OU DES BOULONS DANS LES FENTES (4) DU SOCLE DE MONTAGE. PLAQUE T AN R RT PO ME IM UNT OR F E O M ANS SID TR HER T O CONDUCTEURS DES CONNEXIONS PRIMAIRES BORNES Á VIS DES CONNEXIONS SECONDAIRES SOCLE DE MONTAGE (2) MF20659A Fig. 10. Montage sur socle du transformateur AT87.
PAGE 12
TRANSFORMATEURS AT AT20, AT40, AT72D, AT87, AT88 CÂBLAGE 2 1. 2. 3. Couper l'alimentation électrique avant d'installer le transformateur. Le câblage doit être conforme aux codes et aux règlements d'électricité locaux. Poser un ruban sur chacun des conducteurs à découvert non utilisés. Raccorder les conducteurs primaires à l'alimentation secteur. Voir les Fig. 11 à 13. Raccorder les conducteurs secondaires du transformateur au système de régulation 24 V c.a. 2 COMMUN NOIR 120 V C.A. BLANC 208 V C.A.