Honeywell T874A,D Zone Thermostats Installation Instructions
Honeywell T874A,D Zone Thermostats Installation Instructions for the Trained Service Technician
Honeywell T874A,D Zone Thermostats Application
These T874A,D Zone Thermostats and Q674B,D,E Subbases provide 24 to 30 Vac temperature control in Honeywell Trol-A-Temp heating/cooling zone systems. See Table 1 for thermostat/subbase and system compatibility; see Table 2 for thermostat specifications. For complete Honeywell Trol-A-Temp System specification and application information, refer to the system specification included with the control panel.
TABLE 1—THERMOSTAT/SUBBASE AND SYSTEM COMPATIBILITY
Thermostat/ Subbase Model Numbera |
Application |
Stages |
||
Mini-Zone |
Mabs II, Mabs II-L |
Mabs XX |
||
T874A/Q674B |
Zone 1; conventional heat-cool. |
Zone 1; conventional heat-cool. |
Any zone; conventional heat-cool. |
Single-stage |
T874A/Q674D |
Zones other than zone 1; conventional heat-cool. |
Zones other than zone 1; conventional heat-cool. |
Not applicable |
Single-stage |
T874A/Q674E |
Not applicable |
Not applicable |
Any zone; conventional heat-cool. |
Single-stage |
T874D/Q674B |
Not applicable |
Zone 1; conventional heat-cool. |
Any zone; conventional heat-cool. |
Multistage |
T874D/Q674D |
Not applicable |
Zones other than zone 1; conventional heat-cool and heat pump. |
Not applicable |
Multistage |
T874D/Q674E |
Not applicable |
Not applicable |
Any zone; conventional heat-cool. |
Multistage |
a Subbase not included with thermostat; order separately.
Thermostat/Subbase Order Numbera |
Switching |
Thermostat/ Subbase Color |
Anticipator Range (A) |
||
Heating (Adj.) |
Cooling (Fixed) |
||||
System |
Fan |
||||
T874A1465/Q674B1471 |
HEAT-OFF-COOL |
ON-AUTO |
White/Gray |
Stg. 1—0.1 to 1.2 |
Stg. 1—0 to 1.5 |
T874A1465/Q674D1123 |
None |
None |
White/Gray |
||
T874A1465/Q674E1379 |
HEAT-OFF-COOL-AUTO |
ON-AUTO |
White/Gray |
||
T874D1801/Q674B1463 |
HEAT-OFF-COOL |
ON-AUTO |
Beige/Brown |
Stg. 1—0.1 to 1.2; Stg. 2—0.1 to 1.0. |
Stg. 1—0 to 1.2; Stg. 2—0 to 1.0. |
T874D1827/Q674B1471 |
HEAT-OFF-COOL |
ON-AUTO |
White/Gray |
||
T874D1801/Q674D1115 |
None |
None |
Beige/Brown |
||
T874D1827/Q674D1123 |
None |
None |
White/Gray |
||
T874D1827/Q674E1379 |
HEAT-OFF-COOL-AUTO |
ON-AUTO |
White/Gray |
a Subbase not included with thermostat; order separately.
Honeywell T874A,D Zone Thermostats Operation
On a 2-heat thermostat, the two stages of heat make sequentially as the temperature drops. Make refers to the mercury switch initiating a call for heat or cool. There are about 2° F [1° C] between stages so that the second stage makes only when the first stage cannot handle the load. This is the interstage differential.
Honeywell T874A,D Zone Thermostats 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 product operation as provided in these instructions.
Readmore and Download Honeywell T874A,D Zone Thermostats Manual PDF
Title | : Honeywell T874A,D Zone Thermostats Manual PDF |
Format | |
Pages | : 20 Pages |
Language | : English |
File Size | : 3 MB |