Use and Care Manual

31
110637-01 - 5/20
RRO Installation & Service Manual
10 Operating (continued)
(P) will equal the High Limit Setpoint.
b. High Limit Differential (HdF)
i. The Cold Start Boiler Control is factory
programmed with a Differential of
15°F. The Differential is the number of
degrees the boiler temperature must
decrease below the Operating Setpoint
before the boiler can restart. The
differential is adjustable between 10°
and 30°F.
ii. On Warm Start Boiler Control the High
Limit Differential is not adjustable and is
fixed at 10°F.
c. Low Limit (LL_)
The Warm Start Boiler Control is factory
programmed with a Low Limit Setpoint
of 110°F. On falling temperature the
boiler turns “on” and the “ZC” terminal
and System Circulator outputs are de-
energized when the boiler temperature is
less than the Low Limit Setpoint less the
differential. On a rising temperature when
the boiler temperature is above the Low
Limit Setpoint the boiler turns “off”, the “ZC”
terminal output is energized and the System
circulator is enabled to respond to a call for
heat. The Low Limit Setpoint is adjustable
between 110°F and 220°F.
d. Low Limit Differential (Ldf)
The Warm Start Boiler Control is factory
programmed with a Low Limit Differential
Setpoint of 10°F. The Low Limit Differential
is the number of degrees the boiler
temperature must decrease below the Low
Limit Setpoint before the Warm Start Boiler
Control takes actions to warm the boiler.
These actions include starting the burner
and stopping water flow through the boiler.
The Low Limit Differential is adjustable
between 10°F and 25°F.
e. Circulator Overrun Time (OR_)
Circulator Overrun Time (also called
“circulator off delay” or “circulator post
purge”) continues circulator operation after
a call for heat has ended, sending excess
heat from the boiler into the priority zone.
Ensure system piping and zone panel
settings allow water flow to the priority zone
after the call for heat ends. The Circulator
Overrun Time has a factor setting of 0
minutes and is field adjustable between 0
and 10 minutes.
f. Circulator Pre-Purge Time (PP_)
When the boiler is warm [boiler water
5. Changing the Adjustable Parameters
To adjust parameters such as the High Limit
Setpoint and High Limit Differential:
a. Using the Boiler Control display, access
the adjustment mode by pressing and
holding the Up ñ, Down ò, and “
I” keys
simultaneously for three (3) seconds.
This procedure is intended to discourage
unauthorized changes or accidental
changes to limit settings.
b. Press the "I" key to display available
Adjustment Mode options. Select an option.
Cold Start Boiler Control
Adjustment Mode Options
HL_
140-240°F Adjust High Limit Setting
HdF
10-30°F Adjust High Limit Differential
ZC_ dh, ZR or ELL
ZC and ZR Terminal Function
Or_
0-10 minutes Pump Overrun Time
PP_
2-20 minutes Pump Pre-purge Time
t_
140 - 180°F Start Temperature
Pt_ On or Off
Priority Time
f-C F or C
Select degrees F or C Mode
bac
Back to Operating Mode
Warm Start Boiler Control
Adjustment Mode Options
HL_
140-240°F Adjust High Limit Setting
LL_
110-220°F Adjust Low Limit Setting
Ldf
10-25°F
Adjust Low Limit Differential
Setting
ZC_ ZR or dh
ZC and ZR Terminal Function
Or_
0-10 minutes Pump Overrun Time
PP_
0-20 minutes Pump Pre-purge Time
t_
140 - 180°F Start Temperature
Pt_ On or Off
Priority Time
f-C F or C
Select degrees F or C Mode
bac
Back to Operating Mode
c. Press the Up ñ and Down ò keys to adjust
the displayed setpoint to the desired value.
d. To return to the normal operating mode
from the Adjustment Mode, when the "bc”
option is displayed, press either the Up
ñ or Down ò key. If no keys are pressed,
after five (5) minutes the Boiler Control will
automatically return to the Operating Mode.
6. More Information about Adjustable
Parameters
a. High Limit (HL_)
The Boiler Control is factory programmed
with a High Limit Setpoint of 180°F. The
boiler turns "off" when the boiler water
temperature (bt) is above this value. The
High Limit setpoint is adjustable between
140° and 240°F. The Operating Setpoint