User Guide

2 T-5800 Product Bulletin
provides a change in the input
“CV” pressure. The controlled
variable is compared, by the
internal circuitry, to the set point
pressure. Based on the gain
setting, the unit produces an
output pressure signal change
which is proportional to the
difference between the set point
pressure and the controlled
variable pressure.
In addition, the T-5800-3 has a
master input “M” connection
which serves to readjust the set
point value of the receiver-
controller in accordance with a
predetermined schedule.
Proportional Plus
Integral (PI) Control:
T-5800-2 & T-5800-4
A proportional plus integral (PI)
receiver-controller is basically a
proportional receiver-controller
with a mechanism incorporated
to automatically increase the
gain setting as a function of
time. This integral time is field
adjustable and factory set at
approximately 3 minutes (per
repeat). As the gain increases,
less offset results between the
set point and the controlled
variable. As the gain
approaches its maximum
setting, this offset is virtually
undetectable.
The T-5800-2 and T-5800-4
PI Receiver-Controllers have an
automatic/manual integral
control cutout feature which
allows the system to start up
using proportional-only control.
This feature keeps the system
from going out of control on
startup, as is inherent to PI
(automatic reset) controllers,
when the system has been off
for some time.
PI control is specifically
designed for closed loop
arrangements utilizing
modulating controlled devices,
where the control point offset
associated with proportional-only
control is undesirable. Static
pressure of supply fans, return
fan volume control, and chilled
water temperature
Specifications