Department Of Energy Compliance - Weil-McLain CGi Series 3 Installation And Maintenance Manual

CG i
GAS-FIRED wATER BOILER- sERIEs a -
Boiler Manual
9
Department of Energy - Compliance
This boiler is equipped with a control system that a utomatically adjusts a time delay period to turn on the boiler
during a call for heat. This is accomplished by circulating available hot water in the system while measuring
water boiler water temperature changes. The control calculates a suitable delay based on temperature measure-
ments and turns the boiler on only after it determines that the demand for heat cannot be satisfied with the
available hot water.
Due to the wide variety of controls used in boiler installations, this control is also equipped with an adjustment
for the calculated time delay period (ECONOMY ADJUST). In the MIN position, the time delay is zero and the
IMPORThNT notice below must be observed:
IMPORTANT
In accordance with Section 325 (f) (3) of the Energy Policy and Conservation Act, this boiler is equipped with
a feature that saves energy by reducing the boiler water temperature as the heating load decreases. Th is feature
is
equipped with an override wh ich is provided primarily to permit the use of an e.nernal energy management
system that serves the same function.
T HIS OVERRIDE MUST NOT BE USED UNLESS AT LEAST ONE O F THE FOLLOWING CONDITIONS IS TRUE:
An external energy management system is installed that reduces the boiler water temperature as the heating load
decreases.
Tilis 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.
9a
Operation - sequence
I . Read Operating instructions
on page
41.
This infom1ation
is also located on a label on the inside of the boiler jacket door
panel.
b. If pilot
does
light and control module senses flame
current, spark generator is turned off and main valve
opens.
2. Raise
room them10stat to call for heat.
a. While attempting to satisfy the heat demand, the control
module monitors the boiler temperature changes via the tem-
perature sensor and determines whether or not the available
hot water will satisfy the demand, only running the circulator.
If additional heat is needed, the sequence continues. When
DH W
(if used) calls for heat, sequence above is bypassed.
3.
Circulator energizes.
Iflimit circuit is closed, the inducer
starts. After pressure switch proves proper airflow, control
module initiates
I
0-second prep urge.
4.
Control module sparks
the pilot and opens pilot valve in
main gas valve.
a. If pilot
does not
light within IS seconds, pilot valve
is closed and spark generator is turned off. Control
module initiates a IS-second postpurge, then starts a
new cycle.
Part Number 550-142-780/0712
s.
The CGi-4 timer relay delays high fire for the first
60
seconds
of main flame.
6. During main burner operation:
a
Control module monitors pilot flame current.
If signal
is lost, main valve doses, spark generator activates and
sequence returns to step
4 .
b.
If power is intenupted,
control system
shuts off
pilot
and main gas valves and restarts at step
1
when power is
restored.
7.
In the event the
limit control shuts down the boiler -
The
control module
doses
the pilot and main gas valves, but keeps
the inducer operating for IS-second postpurge.
37