Install Instructions

43
103876-08 - 1/19
CL
Installation & Service Manual
Table 11: External Low Limit,
Parameter zc_= ell
Call for Heat Circulator Status
T- T
Input
ZR
Input
C1
Output
ZC
Output
off off off on
on off on on
on on off off
off on off off
Call for Heat Circulator Status
T- T
Input
ZR
Input
C1
Output
ZC
Output
off off off off
on off on off
on on on on
off on off on
Table 10: Zone Request, Parameter zc_= zr
limit contact closes (boiler water is cold)
the boiler is started and the "ZC" and "C1"
output terminals are de-energized. When
the "ZR" terminal is de-energized (boiler
water temperature is above setpoint)
the call for heat is ended and the "C1"
terminal is released to operation and the
"ZC" terminal is energized. An External
Low Limit Request is detected by sensing
a voltage on the "ZR" terminal. The Warm
Start Boiler Control does not have the
External Low Limit Option. Refer to Table
11.
7. HydroStat 3250 Plus Sequence of Operation
a. Refer to the HydroStat Instructions
(P/N 104145-01) for all operational instructions.
2. Refer to the "IMPORTANT" notice below.
B. STEAM BOILERS SEQUENCE OF OPERATION
Upon a thermostat call for heat, when provided, the
Oil Primary Control is energized when the steam
pressure is below the L404F Pressure Limit and
water level is above the Low Water Cut-Off. When
energized the Oil Primary Control starts the burner
as follows; blower is started and operates for a
pre-purge time; spark is energized and fuel valve is
opened for ignition trail time; the fuel valve remains
open when flame is proven. The burner fires until
the thermostat is satisfied or the Pressure Limit
setting is reached. The Oil Primary Control stops the
burner by closing the fuel valve and operating the
blower for post-purge time. Upon a drop in pressure,
steam pressure below the L404F Pressure Limit, the
burner will re-start if the thermostat is still calling for
heat. When there is a tankless heater included and
there is no demand for heat, the L4006A operating
control will maintain the boiler water temperature
at the selected setting for proper operation of the
domestic water heater.
The probe low water cut-off will shut down the burner
after a 10 second delay, if the water level in the boiler
drops below the probe level. If the water level is too
low the burner will not be allowed to restart. The low
water cut-off will reset and restart the burner with a
call for heat 30 seconds after the water is returned
to its normal level.
On burner start, if the CAD cell does not see flame
within approximately 15 seconds, primary control
will shut down the burner and enter into a lockout
mode. A lockout is reset by pressing the reset button
located on the primary control. If the flame is lost
while the burner is firing, the primary control shuts
down the burner, enters a 60 second recycle delay,
and repeats the ignition sequence. If after three
(3) trials for ignition, flame is not detected, primary
control will enter into restricted mode. Restricted
mode is reset by holding down the reset button for
15 seconds.
IMPORTANT
This boiler is equipped with a feature that saves energy by reducing the boiler water temperature as the heating
load decreases. This feature is equipped with an override which is provided primarily to prevent the use of an
external energy management system that serves the same function. THIS OVERRIDE MUST NOT BE USED
UNLESS AT LEAST ONE OF THE FOLLOWING CONDITIONS IS TRUE:
• An external energy management system is installed that reduces the boiler water
temperature as the heating load decreases.
• This boiler is not used for any space heating.
• This boiler is part of a modular or multiple boiler system having a total input of
300,000 BTU/HR or greater.
• This boiler is equipped with a tankless coil.
6 Operating (continued)