lp-673 Rev. 000 Rel. 001 Date 8.30.18
29
Figure 25 - Cascade Wiring Detail
D. Wiring a Cascaded System
When wiring the water heater for Cascade operation, select one as the
Master water heater. The remaining water heaters will be designated
Followers. See “Setting Up a Cascade System” for more details.
Connect the DHW Sensor / aquastat / or system sensor and 0-10V (if
When installing a cascaded system, it is important that the water
heaters are the same model.
Failure to follow these instructions will result in improper system
operation, wasted time, money, and possible property damage
and personal injury. Such damages ARE NOT covered by product
warranty.
Figure 26 - Cable Wired to Board
Figure 27 - Installed Resistor
MAX 2.5 FEET
used) to the Master. For the Cascade System to work properly a DHW
sensor / aquastat / or system sensor must be installed. The DHW sensor
/ aquastat should be installed in the storage tank; the system sensor
should be located as near the storage tank outlet in the cascade
system loop as possible. The DHW sensor / aquastat / or system sensor
should be wired to the low voltage terminal strip marked for the DHW
temp sensor. The Master control will use the water temperature from
the sensor to control operation of the Cascade System.
If 0-10V is used, the 0-10V should be wired to the low voltage terminal
strip marked for the 0-10V. If the 0-10V is connected, the Master
control will calculate the water temperature set point based on the
programmed reset curve parameters. If the 0-10V is not connected
the Master control will maintain the fixed water temperature set point
programmed into the control.
1. Connect the cascade communication cables to every unit. See Figure
32. Add resistor to the end of the last follower.
NOTE:
The maximum distance between units is two and a half feet.
See Figure 37. This maximum distance can be increased by connecting
additional wire harnesses together. However, the number of units that
can be cascaded will be reduced by one for every additional harness
used.
NOTE:
It is required to protect the cascade communication cable with
a PVC conduit.
2. Every cable comes with one resistor. Use only one resistor on the
cascaded system. Discard the rest.
3. Connect the system sensor to the Master low voltage terminal strip.
See Figure 37. DHW sensor / aquastat / system sensor / 0-10V must be
connected to the Master only.
NOTE:
The DHW sensor / aquastat / system sensor / 0-10V must be
connected to the Master.
NOTE:
After the cascaded system is set, if you manually turn off the
Cascade Master at the display the entire system will shut down.
NOTE:
After the cascaded system is set, DO NOT turn off a Cascade
Follower at the display until you disconnect the cascade cable.
Figure 28 - Maximum Distance Between Wired Cascaded Units - NOTE:
It is required to protect the cascade communication cable with a PVC
conduit.
Figure 29 - Pump Wiring Detail
Figure 30 - Internal Wiring Terminal Blocks