tekmar 521 Programmable Thermostat Installation - Manual (Page 27)

© 2014 521_D - 01/14
27 of 28 A Watts Water Technologies Company
Technical Data
Programmable Thermostat 521 Two Heat or Heat-Cool (Includes Sensor 079)
Literature 521_A, 521_C, 521_D, 521_Q, 521_U
Control Microprocessor control. This is not a safety (limit) control
Packaged weight 0.6 lb. (290 g)
Dimensions 3-11/16” H x 3” W x 15/16” D (94 x 76 x 24 mm)
Enclosure White PVC plastic, NEMA type 1
Approvals Meets Class B: ICES & FCC Part 15, CE
Ambient conditions Indoor use only, 32 to 122°F (0 to 50°C), RH ≤90% non-condensing
Power supply 10 to 30 V (ac/dc), 50/60 Hz, 1.8 VA, Class 2
Relay 30 V (ac/dc) 2 A, Class 2 circuits
Sensor NTC thermistor, 10 kΩ @ 77°F (25°C ±0.2°C) ß=3892
– Included Slab Sensor 079
– Optional tekmar type # 070, 072, 073, 076, 077, 079, 084
Frequently Asked Questions
Symptom Look for... Corrective Action
Display powering
on and off.
Measure voltage at
wiring terminals R
and C.
The power supply transformer
may have limited VA capacity. A
transformer with a larger VA rating is
recommended.
Heat not on
Mode Off or Cool
Thermostat must be in Mode Heat in
order to provide heating.
Floor Max
The floor has reached the maximum
operating temperature.
Room is too
hot due to floor
heating being on
Floor Min
Lower the Set Floor temperature
setting.
Cooling not on Mode Off or Heat
Thermostat must be in Mode Cool in
order to provide cooling.
Slab Sensor 079 10’ (3 m) wire
Dimensions 3/16” OD x 1-1/2” (5 mm OD x 38 mm)
Enclosure 316 stainless steel, 10’ (3 m) 24 AWG, 300 volt PVC insulated Zipcord
Approvals CSA C US
Operating range -58 to 221°F (-50 to 105°C)
Sensor NTC thermistor, 10 kΩ @ 77°F (25°C ±0.2°C) Я=3892