© Fulton Group N.A., Inc. 2021
3-32
OPERATION
ModSyncSE-User-Manual-211020
SECTION 3
!
WARNING
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. Fulton 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
FIGURE 31 – LEAD / LAG CONFIGURATION SCREEN 4
Lead / Lag Configuration 4
The PID compares the supply temperature to the supply setpoint and creates
a control variable output based on how far away from setpoint the loop
temperature is and how long the loop temperature is away from it.
Proportional Band:
The Proportional Band is a range defined around
the set point. It is expressed as a percentage of 300. In figure 25, a
proportional band of 20% would equal a range of 60F. This would
indicate that the CV% output would equal 0% if the loop temperature
was at setpoint and 100% if the loop temperature was at 60F below
setpoint.
» A broad (Large) proportional band causes a more gradual response
from the controller. Typically, this will reduce setpoint overshoot.
» A narrow (Small) proportional band causes a more rapid response
from the ModSync®. However the system may tend to overshoot.
» Because the ModSync® will normally only have a single boiler on at
low fire at a CV output of 0%, Proportional control is rarely enough
to get the loop temperature up to setpoint. As the temperature
begins to get to setpoint the CV begins to drop off to a point that
the system will stabilize at a point slightly below setpoint. For this
reason it is recommended to use Integral Time in combination with
Proportional to achieve and maintain setpoint.
Integral Time:
The Integral Time set is the amount of time, as
calculated by the controller, required to bring the loop temperature up
to setpoint.
» A broad (Large) Integral will cause a more gradual response from the
controller.
» A narrow (Small) Integral will cause a more rapid response. Note that
if you set a short Integral time, the function will respond very quickly
and may overshoot the setpoint.
