Reset Programming (T775L, T775P, T775R, And T775U Models Only) - Honeywell T775 Series Application Manual And Cross Reference

Reset Programming (T775L, T775P, T775R,
and T775U models only)
To program an output for reset, refer to the values as shown in
the example below and in Fig. 1. 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 (99° C)
when the outdoor temperature is 20° F (-7° C).
• Minimum boiler temperature desired is 160° F (71° C)
when the outdoor temperature is 70° F (21° C).
With the above settings example, when the outdoor
temperature is 50° F (10° C), the effective setpoint is 180° F
(82° C).
Setpoint Offset
NOTE: The Setpoint Offset is used for subsequent outputs
only.
This value is the number of degrees plus (+) or minus (-) that
you want the temperature to be offset from the first output's
setpoint. See Fig. 1. For example, If you want the second
output setpoint to be 10° F (-12° C) less than the first output
setpoint, enter -10° F (-23° C).
°F
220
SP MAX A1
210
(BOILER MAX)
S
200
E
N
190
S
O
180
R
A
170
160
SP MIN A2
(BOILER MIN)
150
140
10
RESET B1
(OUTSD MIN)
Fig. 1. Reset Curve with Offset for Subsequent Outputs.
The reset curve established when programming the first
output (Fig. 1) is then used for all subsequent outputs that are
configured for Reset = YES, and each of those outputs will be
offset from this curve.
RELAY 1
SETPOINT
RELAY 2
SETPOINT
OFFSET
-10°F
20 70
30 40 50 60 80 °F
RESET B2
(OUTSD MAX)
SENSOR B
M24862
T775 SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS
Choose Reset = NO for any outputs you do not wish to reset,
then press the HOME button to record your selection.
NOTES:
1. A single reset curve is programmed for the first
output and is used by all outputs setup for Reset.
2. For subsequent outputs, a setpoint offset is used
if that output is also being Reset.
When Reset is programmed, the home screen conveniently
displays the calculated Heat/Cool setpoint(s) for the outputs
based on the reset curve.
Setback (Optional) Description
The Setback temperature option is available only if scheduling
is enabled or the Digital Input Option is set to Setback.
This value is the number of degrees plus (+) or minus (-) that
you want the temperature to be setback (offset) from the
setpoint at a predetermined time.
For example, if you want the temperature to be 10° F (-12° C)
less than the setpoint during setback mode, enter -10° F
(-23° C). See Fig. 2
In normal operations for heating, the offset will be a negative
value; for cooling, the offset will be a positive value.
Setback (optional) Example:
• Setback of -10° F (-23° C) is used to drop the temperature
at night by 10° F (-12° C).
With the above settings example, when the outdoor
temperature is 50° F (10° C), the effective setback setpoint is
170° F (77° C) 180° F (82° C) setpoint minus the 10° F
(-12° C) setback).
°F
220
SP MAX A1
210
(BOILER MAX)
S
200
E
N
190
S
O
180
R
A
170
SP MIN A2
160
(BOILER MIN)
150
140
Fig. 2. Reset Curve for First Output with Setback Offset.
7
SETBACK
OFFSET
-10°F
20 70
10 30 40 50 60
RESET B1 RESET B2
(OUTSD MIN) (OUTSD MAX)
SENSOR B
80 °F
M24861
63-7147—3