Cascade; Access Modes - Lochinvar 151 - 801 Operation Manual

8
Operating information

Cascade

When multiple water heaters are installed, they can be
wired together in a cascade sequence. A maximum of eight
water heaters can be controlled from a single control. In
this application one water heater would be designated as the
Leader control and all others would be designated as Member
controls. The Leader control can be programmed to use
Lead/Lag or Efficiency Optimization control methods.
Once the Leader water heater receives a call for heat from
a tank sensor, BMS or ModBus, the control will determine
what the set point will be. A fixed temperature set point can
be programmed into the control. See page 34 of this manual
to program the set point.
If the water temperature at the tank is less than the set point
- differential, then the control will initiate a call for heat on
the Cascade (see the Outdoor Armor Water Heater Service
Manual for an explanation of the differential). The Leader
will energize the lead water heater on the Cascade. For a new
startup this will be the Leader water heater.
Sequence of the cascade
To equalize the runtime of all water heaters on the Cascade,
the firing sequence will automatically be changed at set
intervals.
For the first 24 hours after initializing the Cascade, the
sequence will be changed every hour. After that the sequence
will be changed once every 24 hours. The switching on/off
sequence will be as follows:
TIME SWITCHING ON SEQUENCE
Start L-M1-M2-M3-M4-M5-M6-M7
+ 1 hour M1-M2-M3-M4-M5-M6-M7-L
+ 2 hours M2-M3-M4-M5-M6-M7-L-M1
If a water heater locks out, it will automatically be given the
lowest priority for the rest of that 24 hour period.
Night Setback operation with cascade
Night Setback operation of the water heaters within the
Cascade is available. Programming of the Night Setback
will be done through the Leader water heater. Refer to the
Outdoor Armor Water Heater Service manual for information
regarding Night Setback.
38
Outdoor Armor Water Heater

Access modes

User
The user can adjust tank target temperatures by pressing the
NAVIGATION dial when "SETPOINTS" is flashing at the
bottom of the display. The date and time, and the temperature
units can also be changed (see page 35).
Installer
Most parameters are available only to the installer, accessible by
entering the installer password, see the Outdoor Armor Water
Heater Service Manual.
Saving parameters
the Outdoor Armor Water Heater Service Manual)
NOTICE
To save parameters and exit programming:
Press the RIGHT SELECT [SAVE] key and then press the
RIGHT SELECT [HOME] key.
To enter a parameter and continue programming:
Press the RIGHT SELECT [SAVE] key 1 time to return to the
parameter listings; press again to return to the menu listings.
Remember to press the RIGHT SELECT [HOME] key when
finished programming in order to save the changes made.
See the Outdoor Armor Water Heater Service Manual for a
detailed description of parameters and access modes.
Installation & Operation Manual
(reference the Parameter Table in
Please note that the brackets ([]) denote
screen status.