T26 Series Line Voltage Thermostats

Transcription

1 Master Catalog 125 Room Termostats Section T Product/Tecnical Bulletin T26 Issue Date 0296 T26 Series Voltage Termostats Te T26 Series line voltage termostat controls eating and/or cooling units in commercial, industrial, or residential installations. Typical uses are for unit eaters, fan coils, blast coils, electric eat, duct furnaces, or greenouses. Models are available wit Single-Pole Single-Trow (SPST) or Single-Pole Double-Trow (SPDT) switces rated for a variety of applications. Te T26 termostats are also suitable for low voltage applications. Figure 1: T26 Termostat wit Vertical Faceplate Features and Benefits Narrow Differential Voltage Components Switc Box Mounted Models wit Limited Ranges Available Adjustable Hig/Low Range Stops Enclosed Pennswitc Mounting Plate Increases versatility of te termostats, wic may be used on eating and/or cooling over a wide range of voltages (24V, 120V, 240V, or 277V) Provides isolation of electrical circuit from sensing element Provides energy conservation Allows adjustments witin a desired range Provides dust protection for contacts Allows easy mounting and wiring witout removing te cover 1996 Jonson Controls, Inc. 1 Part No , Rev. Code No. LIT

2 I ntroduction IMPORTANT: All T26 Series termostats are designed for use only as operating controls. Were an operating control failure would result in personal injury and/or loss of property, it is te responsibility of te installer to add devices (safety, limit controls) or systems (alarm, supervisory systems) tat protect against, or warn of, control failure. Te T26 standard model termostats provide SPDT control for eating, cooling, or eating and cooling applications. Te T26 as a termoplastic cover wit an Allen-ead locking screw to discourage unautorized tampering. Te termostat consists of a liquid filled sensing element, wic as excellent sensitivity to surrounding air temperature canges. Coupled wit a igly efficient diapragm and lever mecanism, te element operates an enclosed narrow differential Pennswitc. An adjusting knob and easy-to-read dial allow quick selection of te desired setpoint. Te termostat is supplied wit te faceplate installed for vertical mounting and knob adjustment. However, a orizontal faceplate is enclosed for orizontal mounting and knob adjustment if desired. Operating Differential Te operating temperature differential of any selfcontained termostat depends on te following: te velocity of air over te termostat te rate of temperature cange to wic te termostat is subjected te current flowing troug te termostat (amperage load) weter te termostat is operating eating or cooling equipment Figures 2 and sow te operating temperature differentials of te T26 termostats under various load conditions. Te amperage loads are based on te electrical ratings in Table 1. Te air velocity was 25 ft/min (0.127 m/sec) and te rate of temperature cange was 6 F (. C ) per our. For air velocities greater tan 25 ft/min and/or rates of temperature cange less tan 6 F (. C ) per our, te operating differentials will be less tan wat is sown in Figures 2 and. Operating Differential F T26B and T26T Heating T26A and T26S Heating Amperage Operating Differential C Note: Te dark sading applies to non-inductive loads only. Figure 2: Operating Differentials for T26A, T26B, and Heating Side for T26S and T26T Operating Differential F T26T Cooling T26J and T26S Cooling Amperage Figure : Operating Differential for T26J and Cooling Side for T26S and T26T Te eavy lines in Figures 2 and are te nominal operating temperature differential. Production termostats may vary from te norm as indicated by te saded areas. Installation Supplies Needed 2 x 4 in. (51 x 102 mm) wall box (field supplied) screwdriver (slotted standard) marking pencil wire strippers Operating Differential C 2 T26 Series Voltage Termostats Product/Tecnical Bulletin

3 Location Considerations Locate te T26 termostat as follows: on a partitioning interior wall, and approximately 5 ft (1.5 m) above te floor in a location of average temperature away from direct sunligt or radiant eat, outside walls or beind doors, air discarge grills, stairwells, or outside doors away from steam or water pipes, warm air stacks, or eated/uncooled areas Dimensions Mounting Screws (Two Places) Figure 4: T26 Dimensions (in./mm) Mounting and Wiring Mounting Plate Locking Screw Grounding Screw Adjustment Knob Vertical Faceplate Optional Concealed Adjustment Faceplate Mounting Plate Cover Locking Screw Wall Box Figure 5: T26 Series Termostat T26 Series Voltage Termostats Product/Tecnical Bulletin

4 IMPORTANT: Do not remove te termostat cover during installation. Te sensing element must be carefully protected against accidental damage. All wiring and mounting can be completed witout removing te cover. T26A and T26B 1 2 T26J 1! CAUTION: Sock azard. Disconnect power supply before wiring connections are made to avoid electrical sock or possible damage to te equipment. To Heating To Cooling Figure 6: Internal Diagram of T26A, T26B, and T26J Heating To install te T26 termostat: 1. Select te proper mounting location (refer to te Location Considerations section) and install a vertical or orizontal wall box approximately 5 feet (1.2 to 1.5 m) above te floor. 2. Run conduit or cable, as required by national and/or local electric codes, from te wall box to te equipment to be controlled. Leave approximately 6 in. (152 mm) of wire for connection to te termostat terminals.. Remove te mounting plate by loosening te mounting plate locking screw (see Figure 5), and lifting and removing te plate from te base. 4. Pull wires troug te mounting plate and fasten te plate, grounding screw end up, to te wall box wit te screws provided. 5. Strip te wires and connect to te proper terminals on te back of te termostat. See Figures 6 troug 11. Note: Use te terminal screws furnised (8-2 x 1/4 in. binder ead). Substitution of oter screws may cause problems in making proper connections. 6. Ground te termostat to te branc circuit ground as required by National Electric Code and local regulations. 7. Hook te two slots in te termostat base over te tabs on te mounting plate and swing te termostat into place. Pus te wires back flus into te wall box. 8. Securely tigten te mounting plate locking screw. 1 2 To Heating Figure 7: T26S, T26T Wired for Heating Application Cooling 1 2 To Cooling Figure 8: T26S, T26T Wired for Cooling Application 4 T26 Series Voltage Termostats Product/Tecnical Bulletin

5 Heating and Cooling Table 1: Electrical Ratings 1 2 T26A, T26S Motor Ratings 120V 208V 240V 277V AC Full H C H C Manual or Automatic Cangeover Switc To Heating To Cooling Figure 9: T26S, T26T Wired for Heating and Cooling wit Manual or Automatic Cangeover Switc AC Locked Rotor AC Non-inductive Pilot Duty VA, 24 to 277 VAC T26B and Heating Side of T26T AC Full AC Locked Rotor Heating and Cooling AC Non-inductive Cangeover Control Y B R Fan Speed Control (if used) Fan Valve Pilot Duty VA, 24 to 277 VAC Cooling Side of T26T AC Full AC Locked Rotor Pilot Duty VA, 24 to 277 VAC T26J AC Full Figure 10: T26S, T26T on Fan Coil Unit wit Cycling Valve and Continuous Fan (Terminal markings sown for A19CAC cangeover control.) AC Locked Rotor Pilot Duty VA, 24 to 277 VAC Heating and Cooling 1 Cangeover Control 2 Y B R Fan Valve Fan Speed Control (if used) Figure 11: T26S, T26T on Fan Coil Unit wit Cycling Fan and Valve (Terminal markings sown for A19CAC cangeover control.) Adjustments For concealed dial models (wit cover removed), te desired dial setting sould be lined up wit te reference mark on te base of te termostat. (See Figure 12.) Tis will place te desired setting at te 9 o clock position wen te termostat is eld vertically. Range Stops Hig and low range stops can be field adjusted as desired. Use te following procedures to set te ig and low range stops. Note: Energy conservation models ave a fixed factory-set limited range. Te stops are not field adjustable. T26 Series Voltage Termostats Product/Tecnical Bulletin 5

6 Hig Range Stop 1. Set te adjustment knob to te maximum desired temperature setting. 2. Pull te adjustment knob off te termostat cover.. Loosen te bottom cover screw and remove te cover. 4. Wile olding te dial firmly in place, keeping te setting in line wit te reference mark, depress te tab A (see Figure 12) and rotate it clockwise until it is against te stop pin C. 5. Release te tab making sure it fits into te nearest notc. 6. Replace te termostat cover, tigten te bottom cover screw, and replace te adjustment knob. 7. Rotate adjustment knob to desired normal operating setpoint. 4. Wile olding te dial firmly in place, keeping te setting in line wit te reference mark, depress te tab A and rotate it clockwise until it is against te stop pin C. Depress te tab B and rotate it counterclockwise until it is against te stop pin C. See Figure Make sure eac tab fits into te notc closest to te stop. 6. Replace te termostat cover, tigten te bottom cover screw, and replace te adjustment knob. Reference Mark Outside Scale ( F) Inside Scale ( C) Low Range Stop Tab "B" Low Range Stop 1. Set te adjustment knob to te minimum desired temperature setting. 2. Pull te adjustment knob off te termostat cover.. Loosen te bottom cover screw and remove te cover. 4. Wile olding te dial firmly in place, keeping te setting in line wit te reference mark, depress te tab B (see Figure 12) and rotate it counterclockwise until it is against te stop pin C. 5. Release te tab making sure it fits into te nearest notc. 6. Replace te termostat cover, tigten te bottom cover screw, and replace te adjustment knob. 7. Rotate adjustment knob to desired normal operating setpoint. Dial Lock Te ig range stop and low range stop can be set to keep te adjustment knob from rotating. To lock te dial: 1. Set te adjustment knob to te desired temperature setting. 2. Pull te adjustment knob off te termostat cover.. Loosen te bottom cover screw and remove te cover. Hig Range Stop Tab "A" Stop Pin "C" Sensing Element Figure 12: T26 Termostat Range Tabs and Stop Ceckout Procedure Before applying power, make sure installation and wiring connections are according to job specifications. After all necessary adjustments and electrical connections ave been made, put te system into operation and observe at least tree complete operating cycles before leaving te installation. Repairs and Replacement Field repairs must not be made except for replacement of te adjustment knob, cover, faceplate, or mounting plate. Refer to Table 4: Replacement Parts for replacement part ordering information. For a replacement T26, contact te nearest Jonson Controls representative. 6 T26 Series Voltage Termostats Product/Tecnical Bulletin

7 O rdering Information Table 2: Ordering Information Item Termostat, SPST, Heating Termostat, SPST, Heavy Duty Heating Termostat, SPST, Cooling Termostat, SPDT, Heating, Cooling, or Heating and Cooling Termostat, SPDT, Heavy Duty Heating, Cooling, or Heating and Cooling Product Code Number T26A T26B T26J T26S T26T Table : Faceplate Ordering Information (For T26 1 Termostats wit Plastic Cover) Kit Number Mounting Position Adjustment Type Termometer Cutout Temperature Scale PLT-1R 1 Vertical Knob Yes Fareneit PLT-2R 2 Horizontal Knob Yes Fareneit PLT-R Vertical Concealed Yes Fareneit PLT-4R Horizontal Concealed Yes Fareneit PLT-5R Vertical Knob Yes Celsius PLT-6R Horizontal Knob Yes Celsius PLT-9R Horizontal Concealed No n/a PLT-12R Vertical Concealed No n/a 1 Can only be used wit plastic cover assembly, wic was made available in te Fall of Supplied wit standard wolesaler models (vertical is factory installed). Accessories Faceplates Faceplates are available in separate kits for on-te-job installation. All plates ave peel-off backing strips. See Table for faceplate ordering information. Faceplates must be ordered in quantities of ten. Brand Name Faceplates Brand name faceplates are available on quantity orders. Contact Customer Service. Concealed Adjustment Faceplates Concealed adjustment faceplates are available on factory order at no extra cost. For field cangeover, use te concealed faceplate kit and install directly over te faceplate on te cover. Termostat Guards Plastic, wire, or cast aluminum guards are available at extra cost. See te GRD Series in te Jonson Controls HVAC/Refrigeration Controls Catalog. Double Control Trim Plates Double control trim plates are available for vertical mounting of T26 termostats side-by-side on a tree gang vertical box. Tese plates may also be used wit T22, T25, T80, W4, and W45. Dimensions are 5-1/2 in. ig by 9-1/8 in. long (140 mm ig by 22 mm long). Order Part No. PLT21-1R. Energy Conservation Models Termostats are available wit limited eating or cooling ranges. Te standard eating models are te T26A-14 wit a range of 40 to 75 F (4 to 24 C) and te T26A-15 wit a range of 40 to 65 F (4 to 18 C). Te cooling models are te T26J-7 wit a range of 75 to 90 F (24 to 2 C) and te T26J-9 wit a range of 78 to 90 F (26 to 2 C). Oter limited settings are available on quantity orders. T26 Series Voltage Termostats Product/Tecnical Bulletin 7

8 Replacement Parts Table 4: Replacement Parts Item Cover Assembly for Knob Adjustment Models wit Termometer, F Scale, Vertical Faceplate (Horizontal Faceplate Supplied Unassembled) Termoplastic Pus On Adjustment Knob Termostat Mounting Plate Mounting Plate for Termostat and Selector Switc Double Gang Box Mounting Plate Product Code Number CVR88A-600R KNB26A-600R PLT51A-602R PLT61A-600 PLT21-1R Specifications Product Contact Ratings See Table 1. T26 Series Voltage Termostats Measurement Range Termostat:: 40 to 90 F (4 to 2 C) Termometer: 50 to 90 F (10 to 2 C) Differential Mecanical: Approximately 0.7F (0.4C ) Operating: See Figures 2 and. Ambient Operating Temperatures Sensing Element Termometer Switc 0 to 105 F (-18 to 46 C) Liquid Filled Bi-metal Type Snap-acting Contacts in a Dust-protected Enclosure Material Base: in. (1.27 mm) Cold Rolled Steel Cover: Beige Termoplastic Finis Base: Zinc Plate Dicromate Dipped Cover: Brown Markings on Gold Anodized Aluminum Mounting Wiring Terminals Agency Listings Dimensions (H x W x D) Sipping Weigt Vertical or Horizontal 2 x 4 in. (51 x 102 mm) Wall Box Large 8-2 x 1/4 in. Binder Head Screws UL Guide No. XAPX; File E6688 CSA Class No ; File LR x 2.96 x 2.87 in. (120 x 75 x 7 mm) 1.0 lb (0.45 kg) Te performance specifications are nominal and conform to acceptable industry standards. For application at conditions beyond tese specifications, consult te local Jonson Controls office. Jonson Controls, Inc. sall not be liable for damages resulting from misapplication or misuse of its products. Controls Group FAN E. Micigan Street Master Catalog P.O. Box 42 Printed in U.S.A. Milwaukee, WI T26 Series Voltage Termostats Product/Tecnical Bulletin