Program Change Settings; Stage Settings; Reaction Time; Purge Delay - heat-timer SQ-Elite-8S Installation And Operation Instruction Manual

18 Heat-Timer Corp.

prograM cHange settIngs

To be able to change the SQ-Elite-8S settings the Program/Run Switch must be set to
Program. The switch is located under the Enclosure Wiring Cover for security. The
Enclosure Wiring Cover can be securely closed using a padlock.

stage settIngs

Hold Button: MENU/<System Settings>/<Stage Settings>

reactIon tIMe

Adjustable from 1 to 10 minutes
Hold Button: MENU/<System Settings>/<Stage Settings>/Reaction Time i n PID Logic only
• Available in PID Control Logic only (See PID Operation on page 5).
• It is the amount of time it takes a single stage to affect the system.
• After the SQ-Elite turns on a stage trying to meet a set point, it will not turn on another
stage until the Reaction Time has elapsed. Then, it will recalculate if a stage is need.
• To determine the optimum time, in a heating system start with a hot system. Then, turn
on a single stage and calculate how long it takes until the system begins to respond to
that stage. That period should be set as the Reaction Time.

purge delay

Adjustable from 0.0 to 10.0 minutes
Hold Button: MENU/<System Settings>/<Stage Settings>/Purge Delay i n PID Logic only
• Available in PID Control Logic only (See PID Operation on page 5).
• Most large boilers must go through a purge cycle before they are brought on line.
• When the SQ-Elite-8S activates a stage (the lowest stage on a boiler), it does not start to calculate its output until the Purge
Delay is over. This allows the boiler to fully come on line and to begin producing output.
• The Purge Delay helps prevent short cycling of a newly activated boiler. Once the lowest boiler stage is activated, it MUST run
through the entire Purge Delay period.
• The minimum Purge Delay setting MUST be set to the time required by the boiler's manufacturer specification.

MInIMuM runtIMe

Adjustable from 1 to 60 minutes
Hold Button: MENU/<System Settings>/<Stage Settings>/Min Runtime i n PID Logic only
• Available in PID Control Logic only (See PID Operation on page 5).
• This is the minimum amount of time any stage will run.
• For the lowest stage of a boiler, the Minimum Runtime starts after the purge cycle.
• This timer does not apply to the last stage online. The Last Stage Hold applies in that case.
• Initially, set the Minimum Runtime to half the Reaction Time.
• If System tends to overshoot, reduce the Minimum Runtime. If boilers tend to short cycle, increase Minimum Runtime.

standby delay

Adjustable from 1 to 60 minutes
Hold Button: MENU/<System Settings>/<Stage Settings>/Standby Delay i n PID Logic only
• Available in PID Control Logic only (See PID Operation on page 5).
• Standby boilers are used as a backup for extreme load conditions only. A standby boiler
can never be a Lead Stage. The Standby Delay only applies to boilers in Standby Mode.
• A Standby unit can only be activated after all the units in Auto Mode have run at high
fire for the full Standby Delay.
• The full Standby Delay must always elapse regardless of what happens to system pressure. Therefore, a shorter Standby Delay
will result in smoother set point operation in extreme conditions. However, longer Standby Delays may prevent a Standby
boiler from starting if the other boilers can eventually meet the load, or if the load decreases.
• When more than one boiler is set as a Standby boiler, remember that it will be added to the Reaction Time for the first stage on
the first Standby boiler only. The following stages and boiler start time will rely on Pre-Purge and Reaction Time only.
Default: 2 minutes
Default: 2.0 minutes
Default: 2 minutes
Default: 10 minutes
PROGRAM
-- STAGE SETTINGS --
Reaction Time
Purge Delay 0.0min
Min Runtime
Standby Delay 10min
Lst Stge Hld 5.0psi
Throttle
<Lead Settings>
BACK SELECT
-- REACTION TIME --
2min
[
BACK
--- PURGE DELAY ----
0.0min
[
BACK
- MINIMUM Runtime -
2min
[
BACK
-- STANDBY DELAY --
10min
[
BACK
RUN
1min
2min
2psi
SAVE
]
SAVE
SAVE
SAVE