Honeywell T775R2027 User Manual

INSTALLATION INSTRUCTIONS
62-0249-13
T775R Series 2000 Electronic
Stand-Alone Controller
PRODUCT DESCRIPTION
The T775 electronic stand-alone controllers are the next
generation of commercial and agricultural controls
capable of remote sensing of temperature and providing
switched and/or proportional outputs to various types of
loads. A built-in time clock is standard.
A Reset function is available for all T775R models where
the Sensor B temperature (e.g. outside temperature) is
used to provide reset control for the Sensor A
temperature (e.g. boiler). For example, as the outside
temperature gets colder, the setpoint temperature
automatically adjusts to save energy.
Three T775R models have analog (modulating) outputs
for actuator and motor control.
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 1. T775R Controller Configurations.
a
All models include a digital input for use with the disable or setback option.
b
The modulating (analog) outputs are 4-20 mA, 0-10 Vdc, 2-10 Vdc, or Series 90 selectable.
c
Each floating output eliminates two SPDT relay outputs.
d
The T775R2043 can support a high/low modulating limit at Sensor B for temperature control at Sensor A.
Controller
Model
a
Description Replaces
SPDT Relay
Outputs
Analog
(Mod)
Outputs
b
Floating
Outputs
c
Sensor
Inputs
Nbr of
Sensors
Included Enclosure
T775R2001 Reset Option N/A 4 None 2 2 2 NEMA 1
T775R2019 Reset Option N/A 4 2 None 2 2 NEMA 1
T775R2027 Reset Option T775J1043
T775J1050
T775J1068
2 2 None 2 2 NEMA 1
T775R2035 Reset Option T775J1001
T775J1076
2None122NEMA 1
T775R2043 Reset Option T775J1019
T775J1027
T775J1035
None 2 None
2
d
2NEMA 1

Honeywell T775R2027 Specifications

General

Brand	Honeywell
Model	T775R2027
Category	Controller
Language	English

Summary

T775 Application Tips

Compatible Components

Lists compatible sensors, actuators, and other components for T775 controllers.

T775 Operations

Integral Action

Explains how integral action minimizes droop and hunting in control loops.

Derivative Action

Describes derivative function's role in PID control to oppose change and speed response.

Differential vs. Throttling Range

Explains the difference between differential for relays and throttling range for modulating outputs.

Setpoint High Limit

Details how to set an irreversible maximum setpoint limit for safety or codes.

T775 Applications

Water Source Heat Pump Loop Water Controller – T775B

Details controlling loop water temperature for heat pumps, including alarms.

Chiller – T775B

Describes controlling sump water temperature for chiller operation and freeze protection.

Chiller, Rotary Compressor – T775B

Explains controlling discharge water temperature for rotary compressors using slide valves.

Cooling Tower Control – T775B2040

Details controlling cooling tower fan speeds and cold weather shutdown based on sump and outside air.

Time-based Control of Fan, Pump, etc. – T775 (all models)

Describes scheduling fan, pump, or other devices based on a daily time schedule.

Damper or Valve Modulation – T775M or T775R

Explains controlling an actuator to modulate a damper or valve based on temperature input.

Hot Water Reset – T775R

Details controlling boiler water temperature with two stages using a reset curve.

Chilled Water Reset – T775R

Describes controlling chiller water temperature based on outside temperature using a reset curve.

Multi-Stage Boiler Control (No Reset) – T775P

Explains multistage boiler control based on discharge water temperature.

Multi-Stage Boiler Control (Reset) – T775P

Details multistage boiler control with reset using discharge water temperature.

Multi-Stage Chiller Control (No Reset) – T775P

Describes multistage chiller control based on discharge water temperature.

4 Stage with Pump Output and Reset – T775P using a T775S Expansion Module

Details 4-stage boiler control with pump output and reset using an expansion module.

3 Stage Reciprocating Chiller – T775L

Explains controlling return water temperature in a reciprocating chiller.

4 Stage Heat and 6 Stage Cool – T775L

Details staged heating and cooling control for boilers and chillers.

Pressure with a Variable Frequency Drive (VFD) – T775U

Describes controlling duct pressure via VFD using a pressure sensor input.

Carbon Dioxide (CO2) Sensing – T775U

Explains controlling an outdoor air damper based on CO2 sensing input.

Resetting Zone Air Temp Based on Outside Air Temp (2 stage cooling)

Details calculating zone air setpoint based on outside air temperature using a reset curve.

Resetting Discharge Air Temp Based on Return Air Temp (Modulating cooling valve)

Explains controlling discharge air temp based on return air temp using a reset curve.

Using the T775R as a Differential Temperature Controller for Solar Water Heating

Details using T775R for solar water heating by controlling circulation pump based on temp differential.

Maintaining Differential Temperature for both Heating and Cooling

Describes maintaining a differential temperature between two sensors for heating and cooling.

T775M2030 Replacement for W973A Logic Panel

Illustrates replacing a W973A Logic Panel with a T775M2030.

T775R Replacement for W964F Aquatrol Panel with Floating Actuator

Shows replacing a W964F Aquatrol Panel with a T775R.

T775L Replacement for S984 Step Controller

Details replacing an S984 Step Controller with a T775L using an expansion module.

T775L Replacement for W7100C Discharge Air Controller

Describes replacing a W7100C controller with a T775L and expansion module.

T775 Cross Reference