AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F Transformers FEATURES PRODUCT DATA AT0 is rated at 0 VA. AT0 is rated at 0 VA. AT50 is rated at 50 VA. AT60 is rated at 60 VA. AT75 is rated at 75 VA. All models meet National Electrical Code Class not wet, Class wet transformer requirements. All models conform to Underwriters Laboratories Inc. Standard UL 55. APPLICATION These general purpose transformers provide power to Vac circuits. They are typically used in heating/cooling control systems, but can be used in any application that doesn t exceed the load ratings. Color-coded leadwires for primary connections and screw terminals for secondary connections, fixed / inch (6 ) male quick-connects or color-coded leadwires for both primary and secondary, are standard. Models available with stripped leadwires, leadwires with variety of terminals, or special terminations as required on both primary and secondary. Mounting options include clamp mounting on outlet box knockout, plate mounting, foot mounting, panel mounting, conduit/panel and a combination. Models available for 0V, 0V, 77V, 0V, 0/0V, 0/0V, 77/0V, 0/0/0V, 0/0/0V, or 0/77/0V supply at 60 Hz. F models include a button for manually resetting the circuit breaker. Contents Application... Features... Specifications... Ordering Information... Installation... Checkout... U.S. Registered Trademark Copyright 996 Honeywell Inc. All Rights Reserved 6-005-5
AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F TRANSFORMERS SPECIFICATIONS replacement value. TRADELINE model specifications are the same as those of standard models except as noted below. IMPORTANT The specifications given in this publication do not include normal manufacturing tolerances. Therefore, a sample unit may not match the listed specifications exactly. Also, this product is built and tested under closely controlled conditions, and some minor differences in performance can be expected if those conditions are changed. TRADELINE Models TRADELINE models are selected and packaged to provide ease of stocking, ease of handling, and maximum TRADELINE Models Available: AT50F Transformers with circuit breaker reset button; 50 VA. AT75F Transformers with circuit breaker reset button; 75 VA. Models: AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F. Electrical Ratings: See Table. Table. Electrical Ratings. Output Rating at Secondary Output Voltage 00 Percent Power Primary Input Voltage At Rated Power Model Number Factor a (60 Hz) Open Circuit Output AT0 0 VA 0, 0, 77, 0, 0/0, 7.0.0 0/0, 0/77, 77/0, AT0 0 VA 0/0/0, 0/0/0, or AT50 50 VA 0/77/0V 7.5 b AT60 60 VA AT75 75 VA arefer to regulation curves. b Voltage is 7.0V on AT50F and AT75F models. Wiring Connections: A, C, and D models: Primary 9 inch (0 ) leadwires; Secondary screw terminals. B and E models: Primary 9 inch (0 ) leadwires or fixed / inch (6 ) quick-connects. Different length leadwires and leadwires with stripped ends or with terminals attached also available. Specify when ordering. Secondary 9 inch (0 ) leadwires or fixed / inch (6 ) quick-connects. Different length leadwires, leadwires with stripped ends or with terminals attached, and screw terminals also available. Specify when ordering. F models: Primary and Secondary 9 inch (0 ) leadwires. ORDERING INFORMATION When purchasing replacement and modernization products from your TRADELINE wholesaler or distributor, refer to the TRADELINE Catalog or price sheets for complete ordering number, or specify. Order number; TRADELINE, if desired.. Primary voltage capability desired.. Wiring connections desired.. Optional specifications, if desired. If you have additional questions, need further information, or would like to coent on our products or services, please write or phone:. Your local Home and Building Control Sales Office (check white pages of your phone directory).. Home and Building Control Customer Relations Honeywell, 5 Douglas Drive North Minneapolis, Minnesota 55-6 In Canada Honeywell Limited/Honeywell Limitée, 5 Dynamic Drive, Scarborough, Ontario MV Z9. International Sales and Service Offices in all principal cities of the world. Manufacturing in Australia, Canada, Finland, France, Germany, Japan, Mexico, Netherlands, Spain, Taiwan, United Kingdom, U.S.A. 6-005 5
AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F TRANSFORMERS Mounting Means: Model Suffix Letter A B C D E F Mounting Means Includes clamp for outlet box knockout, x inch mounting plate for x inch or x inch outlet box, and mounting feet for surface mount. Foot-mounted. Includes clamp for outlet box knockout. Integral x inch mounting plate fits x inch or x inch outlet box. Panel mounted with two No. screws (not included). Includes /- NPSM conduit connector and lock nut for mounting on plate or panel (not included) with 7/ knockout, and mounting feet for surface mount. Dimensions: See Fig. through 5. Regulation: See transformer regulation curves, Fig. 6 through 0. Overcurrent Protection: Inherent on AT0, AT0, and AT50. Thermal fusible link on AT60 and AT75. Circuit breaker on AT50F and AT75F models. Approvals: UNDERWRITERS LABORATORIES INC. LISTED ( A, C and F models): File No. E, Guide No. XOKV. UNDERWRITERS LABORATORIES INC. COMPONENT RECOGNIZED ( B, D, E models): File No. E, Guide No. XOKV. All models conform to Underwriters Laboratories Inc. Standard UL 55. NATIONAL ELECTRICAL CODE: Class not wet, Class wet. Optional Specifications: End bells or caps on B through E models. Terminations on B through E models. Circuit breaker reset button on F models. National Electrical Code: Class not wet, Class wet 6-005 5
AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F TRANSFORMERS PLATE OR OUTLET BOX MOUNTED AT CLAMP ON END BELL PLATE MOUNTED AT THE LAMINATIONS A MAX. (7) 6 B MAX. FOOT MOUNTED C MAX. (9) D () 6 () () (60) 6 () 6 (5) (0) Model AT0 AT0 0, 0/0V 0/0/0V AT50 AT75 -/ -/ A B C D 70 76 76 76 9-7/ -/ -9/6 5 5 5 65-5/6 -/ -/ -5/6-5/ 75 79 79 75 9-7/6-9/6 -/ -/ -/ 7 0 5 Fig.. A model transformer dimensions in (). FOR AT0 MODELS, -5/6 (9). FOR AT0 MODELS, -7/ (7). FOR AT0 MODELS, -7/6 (7). FOR AT0 MODELS, -7/ (). M 6-005 5
AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F TRANSFORMERS A /6 (5) D G (MAX) B C F / (0) E "B" MODELS AVAILABLE WITH MOUNTING FEET; "E" MODELS ARE LESS MOUNTING FEET. AVAILABLE WITH LEADWIRES OR FIXED / [6 ] MALE QUICK- CONNECTS. SCREW TERMINALS AVAILABLE ON SECONDARY. MOUNTING HOLES STANDARD ON "E" MODELS ONLY. / (6 ) ON AT75B. /6 () Model AT0 AT0 AT50 AT60 AT75 -/6 -/ -/ -/ -/ A B C D E F G 7 79 79 6 6 7/ 7/ -/ -/ 5 5 5 /6 /6 7/ 7/ 7/ 5 5 6 6 6 5/6 /6 7/ -/ -7/6 7-5/ -/ -/ -/ -/ -7/ -9/6-9/6-9/6-9/6 65 65 65 65 -/ -/6 -/ -/ -/ M07 Fig.. B and E model transformer dimensions in (). (6) () () (60) (6) (6) 6 (5) 6 (5) 6 (06) 5 6 () () Fig.. Mounting plate dimensions in (). Mounting plate is shipped with A model transformers and attached on D model transformers. M 5 6-005 5
AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F TRANSFORMERS "C" MODEL TRANSFORMER MOUNTED ON OUTLET BOX KNOCKOUT B D A C TOP VIEW 7 () 7 () () SIDE VIEW (6) 7 (7) 6 () "D" MODEL (60) (6) (6) D 6 (5) 6 (5) 6 (06) C 5 6 () () FRONT VIEW B 7 () SIDE VIEW Model AT0 AT0 AT50 AT75-7/ -/ -/ -/ A B C D /6 -/6 -/6 -/ 7 7-5/6 -/ -/ -/ 9 -/ -5/ -5/ -5/ 67 67 67 Fig.. C and D model transformer dimensions in (). SECONDARY AVAILABLE WITH LEADWIRES, FIXED / (6 ) MALE QUICK CONNECTS, OR SCREW TERMINALS. PRIMARY ON "D" MODELS AVAILABLE WITH LEADWIRES OR FIXED / (6 ) MALE QUICK CONNECTS. M 6-005 5 6
AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F TRANSFORMERS 7/6 () A Model AT50F AT75F -/ -/ A B C 5 5 -/ -/ 5 5-5/ -5/6 9 0 B 7/6 () -/6 () /6 (7) -/6 (56) C M5 Fig. 5. F model transformer dimensions in (). SECONDARY VOLTAGE (VOLTS) 5 0 5 0 5 AT0 REGULATION SECONDARY VOLTAGE (VOLTS) 5 0 5 0 5 AT50 REGULATION 0 0.5.0.5.0.5.0.5 0 0.5.0.5.0.5.0.5 SECONDARY CURRENT (AMPS) M0 SECONDARY CURRENT (AMPS) M Fig. 6. AT0 regulation curve. Fig.. AT50 regulation curve. SECONDARY VOLTAGE (VOLTS) 5 0 5 0 5 AT0 REGULATION SECONDARY VOLTAGE (VOLTS) 5 0 5 0 5 AT60 REGULATION 0 0.5.0.5.0.5.0.5 0 0.5.0.5.0.5.0.5 SECONDARY CURRENT (AMPS) Fig. 7. AT0 regulation curve. M SECONDARY CURRENT (AMPS) Fig. 9. AT60 regulation curve. M 7 6-005 5
AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F TRANSFORMERS SECONDARY VOLTAGE (VOLTS) 5 0 5 0 5 AT75 REGULATION USE SCREWS OR BOLTS THROUGH SLOTS () IN MOUNTING FEET "A" MODELS 0 0.5.0.5.0.5.0.5 SECONDARY CURRENT (AMPS) M Fig. 0. AT75 regulation curve. "B" MODELS INSTALLATION When Installing this Product. Read these instructions carefully. Failure to follow them could damage the product or cause a hazardous condition.. Check the ratings given in the instructions and on the product to make sure the product is suitable for your application.. Installer must be a trained, experienced service technician.. After installation is complete, check out system operation as suggested in these instructions. CAUTION Disconnect power supply before beginning installation to prevent electrical shock or equipment damage. USE SCREWS OR BOLTS THROUGH HOLES IN MOUNTING FEET USE SCREWS OR BOLTS THROUGH SLOTS () IN MOUNTING FEET "F" MODELS Foot Mounting ( A, B, and F Models Only) Mount using screws (not supplied) through the two ( B models) or four ( A, F models) holes in the mounting feet. Refer to Fig.. Line voltage primary connections must be made within an approved electrical enclosure. Discard the mounting plate ( A models only). Plate Mounting (Refer to Fig. ) ( A and D models only) Mounting Plate to Transformer ( A models only) Mount the plate to the transformer either: a. at the clamp on the primary end ball OR b. at the laminations. M5 Fig.. Foot mounting. 6-005 5
AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F TRANSFORMERS PLATE MOUNTED AT CLAMP ON PRIMARY END BELL MOUNTING PLATE LEADWIRES FOR PRIMARY CONNECTIONS END BELL SCREW TERMINALS FOR SECONDARY CONNECTIONS CLAMP SCREW AND CLAMP M6 Fig.. When screw is tightened, clamp holds plate on transformer. RAISED PORTION OF LARGE CENTER KNOCKOUT PLATE MOUNTED AT THE LAMINATIONS WITH RAISED PORTION OF KNOCKOUTS FACING YOU:. PRY UP TOP SECTION OF LARGE KNOCKOUT BY INSERTING SCREWDRIVER FIRST AT ONE SIDE OF SLOT AND THEN AT THE OTHER SIDE. LEADWIRES FOR PRIMARY CONNECTIONS MOUNTING PLATE MOUNTING SCREW SCREW TERMINALS FOR SECONDARY CONNECTIONS. THEN PRY UP BOTTOM SECTION OF KNOCKOUT. MOUNTING FEET ON "A" MODELS ONLY. M09 Fig.. On A models, plate may be mounted to transformer in either of two positions. On D models, plate is factory-mounted at laminations. To Mount Plate at Primary End Bell: Turn the screw on the clamp almost completely out. Hold the mounting plate with the keyhole slots up and the raised portion of the large center knockout away from you. From the back, v read the primary leadwires through the round center hole in the plate. Fit the clamp and screw through the round hole. While holding the plate in place, tighten the setscrew securely against the rim of the hole. Refer to Fig.. Avoid damaging the leadwires with the screwdriver.. REMOVE BOTH SECTIONS OF KNOCKOUT WITH PLIERS. SHADED AREAS REPRESENT KNOCKOUTS AND SCREW SLOTS USED WITH X INCH OR OCTAGONAL OUTLET BOXES. Fig.. Use screwdriver to pry out both sections of knockout. M9 9 6-005 5
AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F TRANSFORMERS To Mount Plate at Laminations: Remove the large rectangular knockout in the mounting plate as shown in Fig.. Hold the transformer with the clamp on the end bell facing you. With the keyhole slots up, fit the mounting plate over the primary leadwires and the end bell. Insert the small tab at the bottom of the plate into the slot in the transformer mounting foot. Insert the mounting screw (provided) through the holes as shown in Fig. 5. Secure the plate to the transformer, but do not overtighten the screw. Panel Mounting ( E Models Only) E model transformers are designed for mounting inside a panel using No. screws and washers (obtain locally) through at least two of the four holes in the laminations. Refer to Fig. 6. TRANSFORMER PLATE IMPORTANT MOUNT TRANSFORMER OTHER SIDE M7 Fig. 6. Mounting E model transformer in a panel cutout. Conduit/Panel Mounting Mount the transformer on a plate or panel (not included) with a 7/ knockout. The transformer has a /- NPSM conduit connector and lock nut. M96 NOTE: To meet UL requirements, mount the transformer on a plate or panel with a maximum thickness of 0.5 This allows three and one-half threads of the conduit spud to be exposed after the transformer is mounted. Fig. 5. Secure plate on transformer with mounting screw and tab. Mounting Transformer and Plate on Outlet Box The mounting plate may be mounted on inch square boxes, x inch rectangular boxes, and on inch octagonal boxes. Line up the plate with the box to determine the proper mounting holes. The mounting feet and secondary terminals will be outside the box. Remove the mounting hole knockouts if necessary. Mount the plate on the outlet box using two screws (obtain locally). Mounting Through Outlet Box Knockout ( A and C Models Only) The transformer can be mounted on an outlet box using the clamp on the primary end bell. The mounting plate ( A models only) is not used. To mount the transformer on an outlet box: Turn the clamp screw almost completely out. From outside box, thread the primary leadwires through suitable 7/ inch knockout. Fit the clamp and screw through the knockout. Tighten the clamp screw securely against the rim of the knockout. Avoid damaging the leadwires with the screwdriver. With the conduit connector side of the transformer facing the plate, thread the leadwires through the plate knockout. Insert the connector in the knockout. While holding the plate in place, assemble and tighten the lock nut to fasten the transformer securely. See Fig. 7. Avoid damaging the leadwires with the screwdriver. Make line voltage primary connections within an approved enclosure. MOUNTING PLATE (NOT INCLUDED) LEADWIRES FOR PRIMARY AND SECONDARY CONNECTIONS CONDUIT CONNECTOR LOCK NUT END BELL RESET BUTTON M6906 Fig. 7. Conduit/panel mounting (plate not included). 6-005 5 0
AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F TRANSFORMERS PRIMARY PRIMARY PRIMARY PRIMARY COMMON SINGLE VOLTAGE MODELS 0V COMMON VOLTAGE VARIES WITH MODEL 0V Fig.. Schematic for single and multitap transformers. BLACK 0V - WHITE 0V - RED 0V - ORANGE 77V - BROWN 0V - BLACK/RED 0/0 VAC MODELS COMMON 0V 0V BLACK RED ORANGE BLACK ORANGE SECONDARY SECONDARY SECONDARY SECONDARY CONNECTIONS ARE SCREW TERMINALS, / INCH QUICK-CONNECTS OR BLUE AND YELLOW LEADWIRES. 0V COMMON 77V 0V 0/0/0 VAC MODELS WHITE RED 0/77/0 VAC MODELS 0V BLACK IS COMMON WITH RESPECT TO THE TRANSFORMER WINDING ONLY AND NOT THE EXTERNAL CIRCUIT. SOME MODELS AVAILABLE WITH / INCH QUICK-CONNECTS. BLACK RED BROWN BLACK/RED SECONDARY M0 CHECKOUT CAUTION Do not short transformer secondary terminals. Overload current protection inherent on AT0, AT0, and AT50..5 Amp fuse available on AT60B and AT75A-D. Voltage Check After installation is complete, turn on power supply and perform a voltage check. Place the controlled equipment in operation and observe through one complete cycle. Using a voltmeter, verify proper primary and secondary voltages. If voltage readings are incorrect, ensure primary voltage connections are made properly (refer to Fig. ). Measure voltage aga a. If proper primary voltage is measured and secondary voltage is significantly less than the voltage shown on the regulation curves, transformer winding is damaged. Replace transformer and repeat checkout procedures. b. If primary voltage is 0V, make sure power supply is connected properly or repair if necessary. Repeat checkout procedures. Do not put the system into operation unless correct primary and secondary voltages are measured. Circuit Breaker (AT50F, AT75F Models only) Overloading the AT50F or AT75F Transformer results in tripping the circuit breaker. If the secondary side of the transformer is short circuited, the circuit breaker trips in less than one minute. Reset the circuit breaker by pressing the reset button on the top of the transformer. It can take up to one hour for the transformer to cool, allowing it to reset. If the circuit breaker continues to trip, thoroughly check the system for short circuits and the current draw. Wiring All wiring must comply with local codes and ordinances. Disconnect power before making wiring connections to prevent electrical shock or equipment damage. Make primary connections to the line voltage power supply. On multitap models, make sure to use the correct leads or terminals for the available power supply. Refer to Fig.. On multitap models with leadwires, insulate the ends of the unused leads by taping or capping with a solderless connector. Make secondary connections to Vac control circuit. 6-005 5
AT0A-E; AT0A-E; AT50A,B,D-F; AT60B; AT75A-D,F TRANSFORMERS By using this Honeywell literature, you agree that Honeywell will have no liability for any damages arising out of your use or modification to, the literature. You will defend and indemnify Honeywell, its affiliates and subsidiaries, from and against any liability, cost, or damages, including attorneys fees, arising out of, or resulting from, any modification to the literature by you. Home and Building Control Honeywell Inc. Honeywell Plaza P.O. Box 5 Minneapolis MN 550-05 Honeywell Latin American Division Miami Lakes Headquarters 505 Coerce Way Suite 500 Miami Lakes FL 06 Home and Building Control Honeywell Limited-Honeywell Limitée 55 Gordon Baker Road North York, Ontario MH C9 Honeywell Europe S.A. Avenue du Bourget B-0 Brussels Belgium Honeywell Asia Pacific Inc. Room -5 Sun Hung Kai Centre No. 0 Harbour Road Wanchai Hong Kong Printed on recycled paper containing at 6-005 5 C.B. Rev. -96 Printed in U.S.A. least 0% post-consumer paper fibers. Helping You Control Your World customer.honeywell.com