Weil-McLain Eco Tec 2 Series Advanced Manual page 62

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ECO Tec series 2 gas-fired water boiler – advanced manual
ROTATION AND SEQUENCE
Figure 32 ECO Tec
sequencing options — SMART, PARALLEL or SERIES (examples shown for 3-boiler network)
SMART Sequencing
STAGE 1 – Lead boiler modulates up to a low firing
rate before turning on the next boiler in the sequence.
The STABILIZE TIME allows time for the boilers to
modulate to meet system demand before turning on
additional boilers.
STAGE 2 – Boiler #2 in sequence ignites and both boil-
ers modulate to BASE RATE LOW. After a short MOD
DELAY TIME, the boilers will be released to modulate.
STAGE 3 – Both boilers modulate up to a low firing
rate before turning on the next boiler in the sequence.
The STABILIZE TIME allows time for the boilers to
modulate to meet system demand before turning on
additional boilers.
STAGE 4 – Boiler #3 in sequence ignites and then all
boilers modulate to BASE RATE LOW. After a short
MOD DELAY TIME, the boilers will be released to
modulate.
STAGE 5 – After all available boilers are firing, boilers
are release to modulate up to 100% of rate.
– 62 –
PARALLEL Sequencing
Fewest Running Boilers
Max Efficiency
STAGE 1 – Lead boiler modulates up to a maximum
of Base Rate High before turning on the next boiler in
the sequence. The STABILIZE TIME allows time for
the boilers to modulate to meet system demand before
turning on additional boilers.
STAGE 2 – Boiler #2 in sequence ignites and both
boilers modulate to so their combined energy output
matches the energy output of Boiler #1 at Base Rate
High. After a short MOD DELAY TIME, the boilers
will be released to modulate.
STAGE 3 – Both boilers modulate up to a maximum
of Base Rate High before turning on the next boiler in
the sequence. The STABILIZE TIME allows time for
the boilers to modulate to meet system demand before
turning on additional boilers.
STAGE 4 – Boiler #3 in sequence ignites and then all
boilers modulate to so their combined energy output
matches the energy output of Boilers #1 and #2 at Base
Rate High. After a short MOD DELAY TIME, the boil-
ers will be released to modulate.
STAGE 5 – After all available boilers are firing, boilers
are release to modulate up to 100% of rate.
(continued)
SERIES Sequencing
STAGE 1 – Lead boiler modulates up to a maximum of
100% before turning on the next boiler in the sequence.
The STABILIZE TIME allows time for the boilers to
modulate to meet system demand before turning on
additional boilers.
STAGE 2 – Boiler #2 in sequence ignites and both
boilers modulate to so their combined energy output
matches the energy output of Boiler #1 at 100%. After
a short MOD DELAY TIME, the boilers will be released
to modulate.
STAGE 3 – Both boilers modulate up to a maximum of
100% before turning on the next boiler in the sequence.
The STABILIZE TIME allows time for the boilers to
modulate to meet system demand before turning on
additional boilers.
STAGE 4 – Boiler #3 in sequence ignites and then all
boilers modulate to so their combined energy output
matches the energy output of Boilers #1 and #2 at 100%.
After a short MOD DELAY TIME, the boilers will be
released to modulate.
STAGE 5 – After all available boilers are firing, boilers
are release to modulate up to 100% of rate.
Part number 550-100-272/1021