61
JOHNSON CONTROLS
FORM 100.50-EG12 (918)
Controls
CONTROL SEQUENCES (VAV & SZVAV)
GENERAL
The control system for the Johnson Controls Series 100 single package unit is fully self-
contained and based around a single package unit controller. To aid in unit setup, mainte-
nance, and operation, the single package unit controller is equipped with a user interface
that is based around a 4 line x 20 character backlit LCD display. The LCD displays plain
language text in a menu-driven format to facilitate use.
Based on the unit type (Variable Air Volume (VAV) or Single Zone VAV (SZVAV)), the
Johnson Controls Series 100 Single Package units can be operated by a space tempera-
ture sensor or stand alone. A field wiring terminal block is provided to facilitate unit setup
and installation.
In lieu of the hardwired control options, the single package unit controller can be con-
nected to and operated by a Building Automation System (BAS).
The IPU Controller uses the latest technology and provides complete control for the unit
along with standard BACnet
®
MS/TP and Modbus
™
RTU communications. The IPU also
has an SD card slot that can be used to capture historic data on unit operation.
If required, the unit can be equipped with an optional field installed gateway which allows
N2 or Echelon
®
communications. The E-Link gateway device is field installed and pur-
chased through the Advanced Order Management System (AOMS).
YK-ELNKE01-0 – E-Link for Echelon
YK-ELNKE00-0 – E-Link for N2
UNOCCUPIED / OCCUPIED SWITCHING
Depending on application, the unit can be indexed between unoccupied and occupied
modes of operation by one of three methods, hardwired input, internal time clock, or BAS.
A contact-closure input is provided for hardwiring to an external indexing device such as
a central time clock or a manual switch. The unit controller is also equipped with a built in
7-day time clock which can be used, in lieu of the contact closure input, to switch the unit
between Unoccupied and Occupied modes of operation.
The internal time clock is fully configurable via the user interface and includes Holiday
scheduling. In addition to the hardwired input or the internal time clock, the unit can also
be indexed between unoccupied and occupied modes of operation via a BAS command.
GAS HEATING OPERATION
Units supplied with gas heat can be equipped with one, two, or three independently op
-
erated burner modules. Each module is a fully self-contained furnace with all necessary
ignition controls, safeties, and gas valves. The IPU single package unit controller deter-
mines how the furnaces are started and stopped and prevents furnace operation if the
Supply Fan airflow is not sufficient or if the Supply Air Temperature is excessively high.
If a furnace module receives a signal to start from the IPU controller, the ignition control
engages the furnace inducer (draft) fan for a 30-second pre-purge cycle. At the end of
the 30-second pre-purge, the ignition control will stop the furnace and allows the inducer
fan to operate for a 30-second post-purge. Each furnace contains a direct spark ignition
system and included safeties for flame and inducer fan verification, high temperature and
flame roll-out.