Brochure

T775 SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS
63-7147—3 2
IMPORTANT
The T775R is an operating control, not a limit or
safety control. If used in applications requiring safety
or limit controls, a separate safety or limit control
device is required.
TABLE OF CONTENTS
T775 Application Tips .....................................................3
Compatible Components ...............................................3
Temperature Sensors....................................................3
Humidity Sensors (T775U only) ...................................3
Low Differential Pressure Sensors (T775U only) .........3
Universal Sensors (T775U only) ..................................3
Accessories ..................................................................3
Features ...........................................................................4
T775 Operations ..............................................................6
Integral Action ..............................................................6
Derivative Action ..........................................................6
Differential vs. Throttling Range ...................................6
Setpoint High Limit .......................................................6
Reset Programming (T775L, T775P, T775R, and
T775U models only) .....................................................7
T775 Applications ........................................................... 8
Water Source Heat Pump Loop Water Controller –
T775B .......................................................................... 8
Chiller – T775B ............................................................ 9
Chiller, Rotary Compressor – T775B ......................... 10
Cooling Tower Control – T775B2040 ..........................11
Time-based Control of Fan, Pump, etc. – T775
(all models) ................................................................. 12
Damper or Valve Modulation – T775M or T775R ...... 13
Hot Water Reset – T775R ......................................... 14
Chilled Water Reset – T775R .................................... 16
Multi-Stage Boiler Control (No Reset) – T775P ......... 18
Multi-Stage Boiler Control (Reset) – T775P .............. 19
Multi-Stage Chiller Control (No Reset) – T775P ........ 21
4 Stage with Pump Output and Reset – T775P using
a T775S Expansion Module ...................................... 22
3 Stage Reciprocating Chiller – T775L ...................... 24
4 Stage Heat and 6 Stage Cool – T775L ................... 25
Pressure with a Variable Frequency Drive (VFD) –
T775U ........................................................................ 27
Carbon Dioxide (CO2) Sensing – T775U .................. 28
T775 Application Replacement Examples ................. 29
T775M2030 Replacement for W973A Logic Panel ... 29
T775R Replacement for W964F Aquatrol Panel with
Floating Actuator ....................................................... 32
T775L Replacement for S984 Step Controller ........... 35
T775L Replacement for W7100C Discharge Air
Controller ................................................................... 37
T775 Cross Reference .................................................. 40
Notes ............................................................................. 51