T775P SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLER
19
62-0256—11
Fig. 39. Setup - Outputs - Options - Lead Lag.
1.3.3.8. LEAD LAG
1.
From the Options menu, use the
and
buttons
to highlight LEAD LAG.
2.
Press the
button to display the values
STANDARD, FOFO (First On / First Off), and
EQ RUN (equal runtime).
3.
Use the
and
buttons to select the value.
Default: STANDARD
4.
Press the
button to accept the value and display
the Options menu.
•
Standard
– The controller energizes the stages in
order. For example, if there are four stages, they
energize as 1, 2, 3, and finally 4. Stages de-energize in
the opposite order, 4, 3, 2, and finally 1.
•
FOFO
(First On, First Off) – Serves to help equalize
runtime between stages. The first stage to energize in
a series is the first stage to de-energize. So if stages 1,
2, 3, and 4 energize in that order, then these stages
de-energize in that same order, 1, 2, 3, and finally 4.
•
EQ RUN
(Equal Runtime) – The controller energizes
the stages in the order of lowest run-time. If there are
four stages and the runtime on each stage is as
follows: stage 1 = 6 hours, stage 2 = 3 hours, stage
3 = 4 hours, stage 4 = 10 hours, then the stages
energize 2, 3, 1, and finally 4. Stages de-energize in
the order of highest runtime.
NOTE: FOFO and EQ RUN can be used for up to 12
stages. The run times are tracked for all
stages, however only the run times for stages
1 through 4 display on the home screen.
Fig. 40. Setup - Outputs - Options - DI Options.
1.3.3.9. DI OPTIONS
(digital input options)
The DI Option that you select applies to
all
outputs. This
option overrides any Setpoint/Setback values entered in
the Schedule.
1.
Press the
button to display the DI Option
selections.
2.
Use the
and
buttons to highlight DISABLE,
SETBACK, or IGNORE.
Default: DISABLE
3.
Press the
button to accept the value and display
the SHOW RT menu.
When the digital input (DI) closes, all outputs follow the DI
option value (Disable, Setpoint, Setback, Enable, DHW, or
Ignore):
•
DISABLE
disables the outputs; relays return to de-
energized state.
•
SETPOINT
forces the control to the setpoint
temperature.
•
SETBACK
enables a setback temperature value to be
programmed for each output and forces the control to
the setback temperature.
— To program the Setback temperature with Reset,
— To program the Setback temperature without
Reset, see Fig. 79 on page 31.
•
ENABLE
energizes all relays to 100%. Use this option
carefully.
•
DHW
: if a reset curve is being used, then the
controlled setpoint becomes the maximum setpoint
(either SP MAX A1 or BOILR MAX). If a reset curve is
not being used, then DI closure for DHW has no effect.
•
IGNORE
causes the digital input to have no effect on
the Relay outputs.
SELECT
LEAD LAG
FOR
STAGES
SETUP
OUTPUTS
OPTIONS
LEAD LAG
M24666
STANDARD
FOFO
EQ RUN
SETUP
OUTPUTS
OPTIONS
LEAD
LAG
SELECT DI
OPTIONS
FOR
STAGES
SETUP
OUTPUTS
DI OPTS
M24667A
DISABLE
SETPOINT
SETBACK
ENABLE
DHW
IGNORE
SETUP
OUTPUTS
OPTIONS
DI
OPTS
