Honeywell CM921 Product Specification Sheet

CM921 CHRONOTHERM
6
EN0H 8557 UK07 R0 09/06
R6660D Relay box CMT921A Room Unit
a
b
WIRING
The R6660D relay box is designed for fixed wiring only and must be installed in accordance with latest l.E.E. regulations.
Ensure the wiring connection to the supply is via a fuse rated at no more than 10 amps and a Class "A" switch (having
contact separation of at least 3 mm in all poles).
IMPORTANT
1. The installer must be a trained service engineer
2. Disconnect the power supply before beginning installation
INSTALLATION
• The CM921 is a radio frequency device and for the best performance should be installed in an open space.
• Leave at least 30cm distance from any metal objects including wall boxes and at least 1 metre from any other electrical equipment
e.g. radio, TV, PC etc.
• Do not mount onto metal wall boxes.
• NOTE: It is recommended that the R6660D relay box is installed before commencing with the room unit installation (refer to the
Installation Guide).

Honeywell CM921 Specifications

General

Type	Programmable Thermostat
Display	LCD
Programming	7-day programmable
Power Source	2 x AA batteries
Temperature Range	5°C to 35°C
Mounting	Wall-mounted
Voltage	230V
Frequency	50 Hz
Accuracy	±0.5°C
Control Mode	Heating
Backup	Battery backup