Install Instructions

CG i GAS-FIRED wATER BOILER- sERIEs a- Boiler Manual
9
Department of Energy - Compliance
This boiler is equipped with a control system that automatically adjusts a time delay period to tu rn on the boiler
during a call for heat. This is accomplished by circulating available hot water in the syst em while measuring
water boiler water temperature changes. The control calculates a suitable delay based
on temperature measure-
ments
and turns the boiler on on ly after it determines that the demand for heat cannot be satisfied with the
available hot wat er.
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 Po licy and Conservation Act, this boiler is equipped with
a fea tu re that saves energy by reducing the boiler water temperature as the heating l oad decreases. This feature
is equipped with an override which is provided primarily to permit the use of an e.nernal energy management
system t
hat serves the same function.
T HI S OVE RR IDE MUS T NO T BE USED UNLESS AT LE AST ONE O F TH E FOLL OW I NG COND ITI ONS IS TRUE:
An external energy management system is installed that reduces the boiler water temperature as the h eat i ng load
decreases.
Tilis bo il er is part of a m od ul ar or mul tip le bo il er syste m h avi ng a total input of 300,000 BT U/hr or g rea t er.
This bo il er is equipped with a tan kl ess coil.
9a
Operation - sequence
I . Read Operating instructions on page 41. This in fom 1 atio n
is also located on a labe l on the i ns i de of the boiler jacket door
pane l.
b. If pilot does light and co ntrol mod ul e se n ses fla me
current, spark generator is turned off and m ain valve
opens.
2. Raise room them10stat to call for heat.
a. While attempting to satisfy the heat dema n d, th e control
module monitors
the boile r te mperature changes via the tem -
perature sensor and determi nes whether or not th e ava i lab le
hot water will satisfy th e demand, only running the circulator.
If additional heat is needed, th e seque n ce co n tinues. Whe n
DHW (if u sed) ca ll s f or h ea t, sequen ce above is bypasse d.
3. Circulator energizes. Iflimit circuit is closed, the inducer
sta
rt s. After p ress ure swi t ch proves proper ai rfl ow, control
modu
le initiates I 0-second prep urge.
4. Control module sparks the pilot and opens pilot valve in
m ain 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 - seco nd postpur ge, th en starts a
new cycle.
Pa rt Nu mber 550-1 42-7 80/0712
s. The CGi -4 timer relay de l ays h ig h fir e for th e first 60 seco nds
of main fl am e.
6. During main burner operation:
a Control m od ul e monitors p il ot fl ame cur re n t. If signal
is lost, main valve doses, spa rk generator activates and
sequence returns to step 4.
b. If power is intenupted, control syste m shuts off pilot
and m
ain gas valves and restarts at step 1 when powe r is
r estored.
7. In th e eve nt the limit control shuts down the boiler - The
co n trol module doses the pilot and main gas valves, but keeps
the inducer operating for IS - seco nd postpur ge.
37