Sequence Of Operations - FULTON Vantage VTG Series Installation And Operation Manual

OPERATION
This manual is provided as a guide
to the correct operation and
maintenance of your equipment,
and should be read in its entirety
and be made permanently
available to the staff responsible
for equipment operation. It should
not, however be considered as a
complete code of practice, nor
should it replace existing codes or
standards which may be
applicable. Synex reserves the
right to change any part of this
installation, operation and
maintenance manual without
notice.
Do not install, operate, service, or
repair any component of this
equipment unless you are qualified
and fully understand all
requirements and procedures.
All information in this manual is for
reference and guidance purposes,
and does not substitute for
required professional training,
conduct, and strict adherence to
applicable jurisdictional
/professional codes or regulations.

Sequence of Operations

Designed to maximize the efficiency of a multiple boiler hydronic loop, the ModSync resets
the loop temperature based on Outdoor Temperature. The hydronic boilers are sequentially
staged on at low fire, if additional heat is required; the condensing boilers are modulated
together, keeping at the lowest firing rate possible to match the system load.
A typical Sequence of Operations is as follows:
1. The ModSync monitors the outdoor temperature and calculates a water loop
temperature setpoint based on the selectable preset values. A PID Control Variable
determines when the hydronic boilers will begin sequencing, based on the
difference between the actual water loop temperature and the calculated (by
outdoor air) water temperature setpoint.
2. When the ModSync determines a request for heat, the lead hydronic boiler is
energized and the firing rate is maintained at low Fire.
3. If the water loop temperature continues to decrease, the PID Control Variable will
increase. The lead boiler's firing rate will track the control variable value. The
ModSync will enable a Lag Boiler when the Lag Boiler Start control variable value
has been reached. The Lead and Lag boiler's firing rates will modulate together at
the lowest possible firing rate.
4. If additional heat is required, the ModSync will enable each additional Lag Boiler
until all of the available boilers in the loop have been energized. Each boiler will
remain at the lowest possible firing rate until all of the boilers have been enabled.
5. If all of the boilers are enabled and additional heat is required, the ModSync will
release the boilers to fully modulate. The boiler will modulate together as a single
unit to keep the condensing boiler system at the lowest possible firing rate,
maximizing the hydronic loop efficiency.
6. As the water loop temperature increases, the ModSync will begin to decrease the
firing rate of the boilers to maintain the water loop temperature. If all of the
boilers are at low fire and the control variable decreases to a user configurable
level, the ModSync will begin to stage the boilers off. The first lag boiler energized
will be the last boiler to be disabled. The boilers will continue to be disabled based
on the temperature rise and control variable response.
7. The lead boiler is disabled when the water loop temperature reaches a selectable
value referenced around the water loop setpoint.
MODSYNC-IOM-2016-APR
SECTION 3
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