Honeywell THE T675 AND T6786 TEMPERATURE CONTROLLERS REGULATE THE TEMPERA TRUE OF AIR OR LIQUIDS IN DUCTS, PIPES, TANKS, AND BOILERS. TYPICAL USES INCLUDE CONTROL OF DAMPERS AND VALVES IN HEATING, COOLING, OR HEATING-COOLING SYSTEMS.
TRADE LINE MODELS TRADE LINE models are selected and packaged to provide ease of stocking, ease of handling, and maximum replacement value. TRADE LINE model specifications are the same as those of standard models except as noted below. TRADE LINE MODELS AVAILABLE: ing insert and 107324A Capillary Holder. T675A and T678A Temperature (Models with fast-response sensing element Table | for TRADE LINE models available, include 131524A Capillary Holder.) CAPILLARY: 5 ft [1.
STANDARD MODELS MODELS (also refer to Table 11): switching to break a circuit on a temperature fall; T875A Temperature Controllable switching to must be manually reset. make or break a circuit on a temperature change; T678A Temperature Controller—2 spit switches fast-response models operate approximately 4 operate 2 independent circuits in sequence; fast times faster than standard models. response models operate approximately 4 times T8758 Low Limit Temperature Comptroller faster than standard models.
Differential (cover must be removed): T675A models with adjustable ditterential—adjustment dial on snap-acting switch. T673A interstate differentiation wheel on left side of chassis. MAXIMUM SAFE BULB TEMPERATURE: See Table IL. TEMPERATURE SENSING ELEMENT: Standard element is a liquid-filed, remote bulb. Some models are available with a fast-response, liquid-filled, coiled capillary element which reduces response time to approximately 1/4 that of the standard bulb. SENSING BULB SIZE: in. [106.4 mm].
WHEN INSTALLING THIS PRODUCT. .. 1. Read these instructions carefully. Failure to follow them could damage the product or cause a hazardous condition. 2. Check the ratings given in the instructions and on the product to make sure the product is suitable for your application. 3. Installer must be a trained, experienced service technician. 4, After installation is complete, check out product operation as provided in these instructions.
T675A As the temperature of the controlled medium falls below the set point Jess differential, the T675A switch makes terminals R to B and energizes a normally closed solenoid valve to provide heat. In cooling applications, the T675A makes terminals the temperature rises above the set point, energizing cookie ing equipment. Fig. 7 shows the operation of the T675A. Fig. 8 shows the Location of the adjustment dial on models with an adjustable differential.
TEATS OPERATION sa, Ha REAR pia : fanatic FA a i steak RB. pi (DISPUTABLE! HARE Rui Gv ELL STABLE FROM 3 70.10 STANDARD 716 1016 3 © ON S513 176 F (1370 FIG. 10--OPERATION OF THE T678A. The T678A Temperature Controller has an adjustable interstate differential. The set point adjustment knob determines the temperature at which the right switch operates. The left switch can be adjusted to operate from toff 10F.7 Co 56 Cl or 86 F 10 12F some models) above the point of operation of the right switch.
T678A These controllers are calibrated so that the dial setting, indicated by the pointer on the adjustment knob, is the pointer at which the R-W contacts of the right switch make on a temperature rise. if the temperature continues fo rise, the R-W contacts of the left switch make at the dial setting plus the interstate differential. (The interstate differential is adjustable as shown in Figs. and 11.) Measure the temperature at the bulb. Rotate the adjustment knob counterclockwise »\ from the top of the sc
