Honeywell Q539 user manual

Summary of the content on the page No. 1

Q539A, H and J Subbases

Installation Instruction for the Trained Service Technician.
Application
Q539 Subbases provide cooling anticipators, and mounting for T87F Thermostats. Q539 Subbases also provide system
and fan switching for heating, cooling, and heating-cooling thermostats. For subbase specifications, refer to Tables 1 and 2.
TABLE 1—SUBBASE SPECIFICATIONS.
System Fan See
Model Description Switch Switch Terminals Fig.
Q539A provides system and fan switching and cooling HEAT- AUT

Summary of the content on the page No. 2

Do not mount the subbase where it may be affected by: Fig. 1—Level Q539 using a spirit level . — drafts or dead spots behind doors or in corners. — hot or cold air from ducts. — radiant heat from the sun, fireplaces, or appliances. SPIRIT LEVELING LEVEL POSTS (2) — concealed pipes and chimneys. — unheated (uncooled) areas such as an outside wall. CAUTION • Disconnect power supply to prevent electri­ cal shock or equipment damage. • Do not short across coil terminals on relay, OPENI

Summary of the content on the page No. 3

Settings Fig. 5—Typical hookup for Q539J in heating­ cooling applications. Fan relay operates automatically on heat or cool with fan in AUTO SUBBASE SETTING position The subbase switching positions control the system operation as described below. Q539J/T87F INTERNAL SCHEMATIC SYSTEM SWITCH (some subbases do not have all of the following functions): T87F COOL—cooling system is automatically controlled TEMP. R1 by the thermostat. Heating system is off. FALL FILTER OFF—both the heati

Summary of the content on the page No. 4

COOLING FAN Move the subbase switch to OFF and the fan switch to ON. The fan should run continuously. Move the fan switch to AUTO. In this position, fan operation is controlled by the CAUTION heating or cooling system control circuit. If outside air or heat exchange medium (water) is Operate the entire system one complete cycle with below 10AC (50AF), do not operate cooling. switches in each position before leaving installation. Turn thermostat dial to the desired setting and set the s