Maximum Recommended Thermostat Wire Length - Thermo Pride CMA3-50D36N Installation And Service Manual

Gas fired high efficiency furnace
Hide thumbs Also See for CMA3-50D36N:
Table of Contents

Advertisement

IMPORTANT:
The room thermostat should be installed 4 to 5 feet above
the floor on an interior wall which is relatively free from direct sources of
heat (sunlight or supply airflow) or exposure to cold (drafts from open
windows and doors). The nominal anticipator setting is 0.8 amperes, for
the CMA/CMC (refer to the thermostat literature for additional information).
Four-conductor thermostat wire is recommended for 24 VAC, low-voltage,
control circuit wiring. However, only 2 wires are required for the furnace (a
heating application only).
Electrical Wire
Diameter
(AWG)
24
22
20
18
Once the furnace is installed, check the thermostat anticipator for proper
nominal setting.
1. Connect a multimeter, capable of reading milliamps (mA), in series
with the low voltage wires to the thermostat.
2. Increase the thermostat setting, or create a "call for heat".
3. Read the value of the thermostat current, in milliamps.
4. Adjust the heat anticipator of the thermostat to the value read by the
multimeter.
If the heat anticipator is set too high, the furnace may delay activation of a
heating cycle for too long. If the heat anticipator is set too low, the furnace
may cycle too frequently. Either condition may not provide optimal
comfort to the homeowner.
Maximum Recommended
Thermostat Wire Length
(Feet)
55
90
140
225
32

Hide quick links:

Advertisement

Table of Contents
loading

Table of Contents