Install Instructions

52
5. Setting up Multiple Boiler Operation:
a. Setting the Boiler Address
:
• Press the “Menu” and “Select” keys
simultaneously for 5 seconds to enter the
Installer Menu.
• Use the “
M” key to scroll down to “Cascade
Settings” on the menu.
• Pressing “Select” will cause the Boiler Address
value to blink. Use the “
M” or “L” key to
change the value.
• The master boiler will be designated as Boiler
Address: 1.
• All dependent boilers must have sequential boiler
address settings as shown on the following table.
• Once a boiler is designated as a dependent
boiler, the display will show the individual
boiler supply temperature and its status.
• The master boiler will display the system
temperature and the overall status of the
cascade system.
• By pressing the “
M” or “L” key the operator
can view the master boiler status.
b. Connecting the Cascade Links – PF-50 through
PF-140.
• Remove the User Interface Display from the
boiler by pressing the tab on bottom edge and
rotating it outward and upward as shown in
Figure 8.6.
• There will be two sets of terminals on the sub-
base still attached to the boiler. The first set
will have wires attaching the display to the
Main Control board.
• Attach 2 wires to the second set of terminals
on each boiler to be connected.
• For the Master Boiler only, slide the
switch lever toward the center of the
panel to the “ON” position.
• For all dependent boilers, the switch should
remain in the “OFF” position toward the side
of the printed circuit board.
• Re-assemble the User Interface Display and
connect wires to each boiler in the system.
• All of these wires are to be connected to the
Master Boiler as shown in Figure 8.7.
c. Connecting the Cascade Links – PF-210 & PF-399.
• Remove the User Interface Display from the
Master boiler only.
• Slide the Master Switch Lever toward the center
of the printed circuit board. The Master Switch
Lever is not marked with “ON” or “OFF” but
the switch is in the “ON” position when it is
moved to the left as viewed from the back of the
display. This position is shown in Figure 8.6.
• Re-attach the User Interface Display.
• Connect wires from terminals #11 & #12
between all boilers in the system.
6. Cascade Operation:
a. When a call for Central Heat (CH) or Domestic
Hot Water (DHW) is present, the Master boiler
chooses which boiler will lead based on the
Cascade Rotation Interval
.
b. Before starting the Lead boiler, the Master control
will first check to be sure that the System
temperature is lower than the System Setpoint +
Stop Boiler Differential
.
c. After a Trial For Ignition (TFI), the lead boiler will
modulate its input rate to meet the heat demand.
d. Any time that a boiler is started the Cascade Start
Delay Time will be initiated and no boiler will be
allowed to start before this time elapses. This is to
allow time for the system to stabilize before
bringing on an additional boiler.
e. After the delay time has elapsed, one of the
following conditions must be met before starting
the next boiler:
• The System Temperature must be lower than
the Set Point minus the Cascade Start Boiler
Differential temperature, or
• The input rate of all boilers operating must be
higher than the Next Boiler Start Rate
.
BOILER CONTROL: INTERNAL WIRING & OPERATION
Boiler
Operation
Cascade
Address
System
Sensor
Outdoor
Sensor
DHW
Sensor
Stand-alone
Boiler
0
Not
Active
Active Active
Boiler #1
Master
1 Active Active Active
Boiler #2
Dependent
2
Not
Active
Not
Active
Not
Active
Boiler #3
Dependent
3
Not
Active
Not
Active
Not
Active
➞
➞
➞
➞
➞
Boiler #16
Dependent
16
Not
Active
Not
Active
Not
Active
Table 8.10: Cascade Addresses and Sensor Functions
Figure 8.6: Cascade Link Connection & Switch Setting
To cascade PF-50 and PF-80
models, display must include
On/Off switch and sub-base must
include dual terminal blocks.