Instruction/ maintenance manual of the product T874A Honeywell
Go to page of 10
S. M. • Rev. 6-93 • • ©Honeywell Inc. 1993 • Form Number 69-0580—2 M3375 T874A,D Zone Thermostats/ Q674B,D,E Subbases TABLE 2—THERMOSTAT/SUBBASE SPECIFICATIONS. Thermostat/ Anticipator Range (A) Thermostat/Subbase Switching Subbase Heating Cooling Order Number a System Fan Color (Adj.
Installation WHEN INSTALLING THIS PRODUCT… 1. Read these instructions carefully. Failure to fol- lo w them could damage the product or cause a hazard- ous condition. 2. Check the ratings given in the instructions and on the product to make sure the product is suitable for your application.
3 69-0580—2 letter code is located near each subbase terminal for identi- fication. The terminal barrier permits straight or conven- tional wraparound wiring connection (Fig. 4). 2. Some Q674 Subbases have RC and RH terminals for isolated heating and cooling transformers.
MOUNTING THE THERMOSTAT 1. Remove the thermostat cover by pulling the bottom edge of the cover outward away from the base until it snaps free from the cover clip.
5 69-0580—2 Fig. 8—Typical hookup for MABS II and MABS II-L Control Panels with T874D Thermostat/Q674B,D Subbases in multistage heating-cooling zone system. MABS II Control Panel shown; MABS II-L Control Panel hookup is the same. M1393A Y2 1 POWER SUPPLY.
6 Fig. 9—Typical hookup for MABS XX Control Panel with T874A Thermostat/Q674B,E Subbases in single- stage heating-cooling zone system. M1636 1 2 3 4 5 6 7 8 9 ADD-A- ZONE HEAT FAN COOL HEAT FAN COOL HEAT FAN COOL YW G G h 456 Z DAMPER ACTUATOR 12 3X L1 (HOT) L2 1 MABS XX CONTROL PANEL 1 POWER SUPPLY.
r.
Settings.
9 69-0580—2 Checkout TABLE 5—SYSTEM SET-UP FOR THERMOSTAT CHECKOUT. Heating Cooling Control Zones Other Zones Other Panel Zone 1 Than Zone 1 Zone 1 Than Zone 1 Mini-zone Set thermostat Move the he.
Fig. 14—Thermometer calibration. Calibration THERMOSTAT T874 thermostats are accurately calibrated at the factory. They do not have provision for field calibration. THERMOMETER The thermometer in your thermostat has been accu- rately calibrated at the factory.
An important point after buying a device Honeywell T874A (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Honeywell T874A yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Honeywell T874A - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Honeywell T874A you will learn all the available features of the product, as well as information on its operation. The information that you get Honeywell T874A will certainly help you make a decision on the purchase.
If you already are a holder of Honeywell T874A, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Honeywell T874A.
However, one of the most important roles played by the user manual is to help in solving problems with Honeywell T874A. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Honeywell T874A along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
