Page 22
SECTION 3
Cascade Communications (cascade cable)
3.A Cascade Kit Content and Instructions
A system sensor must be connected to the leader boiler in order to provide feedback for set point
temperature reference and therefore properly control the bank of cascaded boilers.
In order for the system to work properly, the thermostat, 0-10V signal, and/or outdoor sensor must be
connected to the leader boiler only. Following boilers will run based on the Leader boiler’s controls.
Reference Section 4 of the FT Series Heating Only Installation and Operation manual (Doc #1483 Wall or
Doc# 1510 Floor) to set the Leader boiler’s temperature set point based on an outdoor sensor, 0-10V signal
or a fixed temperature set point and the cascade programming for all units.
Item #
Description
Part #
CA017502
2 Boilers
CA017503
3 Boilers
CA017504
4 Boilers
1
FT Cascade Instructions
H2384200
1
1
1
2
Cascade System Sensor
FT1868
1
1
1
3
FT Cascade Communication Cable
w/ ending resistor
FT1861
2
3
4
4
Cable Tie, Plastic, 4"
E0007501
4
6
8
Table 4: Cascade Kit Components
Notes: Perform start-up and combustion calibration of individual FT boilers BEFORE configuring the cascade
system. Refer to Section 4 of the FT Series Heating Only Installation and Operation Instructions for details.
Make sure that power is disconnected (OFF) at boiler before continuing with these instructions.
The FT heating only boilers can be controlled by only the cascade system sensor, either with or without the
outdoor sensor.
The cascade system sensor (FT1868) must be connected to the Leader boiler in order to provide feedback
for the system set point reference and therefore properly control the cascaded boilers.
Refer back to piping diagrams on page 4 through 19 for the proper location of the cascade sensor. Strap the
sensor to the piping and thoroughly insulate the sensor and piping. Connect the sensor leads to terminals
marked Cascade System Sensor terminals on the Leader boiler.
If outdoor reset operation is desired, install the outdoor sensor on the northern side of the building away from
direct sunlight or other heat sources. Route the control wiring back to the O/S terminals on the Leader boiler.
Avoid running this control wiring parallel to 120 V lines.
Components Needed : (included in cascade kit)
FT1868
: System Sensor (need only 1).
FT1861
: FT Series Cascade Communication Cable (1 per unit) with Ending Resistor.
Example. If you are cascading 6 units, you will need
6
X
FT1861
’s and you will not use 5 of the resistors.
3.B Wiring Connections for Cascade
NOTE: The control boards for the FT Floor and FT wall-mount units are different and can NOT be interchanged.
