T775P SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLER
62-0256—11
26
2. PROGRAMMING OUTPUT
STAGE(S)
WITH RESET
The T775P can be programmed for Reset or No Reset.
From the factory, the T775P is programmed for No Reset.
This section describes the steps necessary to program
the controller for Reset.
To use the Reset feature, the Reset Option must be set to
Reset=YES in Setup mode (see “2.1. Setting Up the
Fig. 63. Reset Setup.
2.1. Setting Up the Controller for Reset
1.
Press and hold the
MENU
button for five seconds to
enter Setup mode.
2.
Then choose:
OUTPUTS
OPTIONS
RESET
then select YES-BOILER or YES-OTHER as shown
in Fig. 63.
You can now press the
HOME
button to exit Setup mode
and continue with “Determining and Setting the Reset
Determining and Setting the Reset
Values
NOTE: When using the Reset feature, Sensor A must
be sensing the controlled temperature (e.g.
boiler), Sensor B must be sensing the
resetting temperature (e.g. outdoor temp).
To program an output with Reset, refer to the values as
shown in the examples below and in Fig. 64. Choose your
own appropriate values for Sensor A maximum and
minimum and Sensor B maximum and minimum.
Reset Example:
• Sensor A is the boiler sensor and Sensor B is the
outdoor sensor.
• Maximum boiler temperature desired is 210°F when
the outdoor temperature is 20°F.
• Minimum boiler temperature desired is 160°F when the
outdoor temperature is 70°F.
• With the above settings example, when the outdoor
temperature is 50°F, the effective setpoint is 180°F.
Setback Example (Optional):
• Setback of -10°F is used to drop the temperature at
night by 10°F.
• With the above settings example, when the outdoor
temperature is 50°F, the effective setback setpoint is
170°F (180°F setpoint minus the 10°F setback).
CAUTION
If using the time clock or DI to go to setback,
the T775P will shift the reset curve up or down
and cause the controlled setpoint to exceed
either the entered reset max. temp or min.
temp (dropping below reset minimum is most
common, since setback is normally below
setpoint). If this is not desired, either do not
use setback, or adjust the min. and max.
values entered so that critical setpoints are
not exceeded in the setback mode.
When Reset is programmed, the home screen
conveniently displays the calculated Heat/Cool setpoint
for the Stages based on the reset curve. See Fig. 15 on
Fig. 64. Reset Curve with Setback Setpoint.
The remainder of this section beginning with “2.2. Program
Menus for Reset” on page 27 describes the individual
parameters for configuring the controller with Reset.
For your reference, the following Reset programming
procedure uses the values in Fig. 64.
SETUP
OUTPUTS
OPTIONS
RESET
SETUP
OUTPUTS
OPTIONS
RESET
USE RESET
FOR
STAGES
YES-BOILER
YES-OTHER
NO
M24420
SENSOR B
SP MAX
SP MIN
200
140
10
190
20
30
40
50
60
70
°F
80
150
160
170
210
220
180
°F
RESET B1
RESET B2
S
E
N
S
O
R
A
M24535
SETBACK
SETPOINT
-10°F
