Lochinvar 1.3 service manual Cascade Parameters Screen, Service Manual, Cascade Operation

1 Service (continued)

Cascade Parameters Screen:

Cascade Operation

When multiple boilers are installed, they can be wired together in a cascade sequence. A maximum of eight (8) boilers can be controlled from a single control. In this application one boiler would be designated as the Leader and all others would be designated as Members. The designated Leader boiler determines the total output needed from the group based on the set point and the system sensor reading. Reference the Wiring of the Cascade section in the SYNC Installation and Operation Manual for more information regarding the cascade feature.

The Cascade Screen allows access to four (4) parameters. Those parameters are as follows:

•Cascade Address - The boiler designated as the Leader should be programmed with address 0-1. All Member boilers require addresses from 2-3 through 14-15. The address must be different for each member. The addresses can be in any order, regardless of the order in which the boilers are wired together. This parameter can only be changed by the installer. The default address is 0-1.

•Cascade Off Differential - Sets how many degrees above set point the temperature has to go before the lead boiler will shut off. This parameter can only be changed by the installer. The temperature range of this parameter is 0° to 72°F. The default value is 10°F.

Service Manual

•Cascade Off/On Differential - Sets how many degrees below the turn off temperature (set point + Cascade Off Differential) the temperature has to go before the lead boiler will turn on. This parameter can only be changed by the installer. The temperature range of this parameter is 0° to 72°F. The default value is 20°F.

•Maximum Outlet Temperature - Sets the set point that individual boilers will attempt to achieve in a cascade. When a boiler is commanded to fire by the Leader, it will attempt to achieve this temperature at its outlet. The Leader will control the modulation of the last boiler to fire in order to hold the temperature at the system supply sensor to the user set point. If any of the boiler outlet temperatures reach the Maximum Outlet Temperature setting, the boiler will then modulate down on its own in order to keep its outlet temperature within the Maximum Outlet Temperature setting. Therefore, this parameter can be used to limit the outlet temperatures of all the boilers in a cascade.

Note that this parameter does not apply when the boiler is in Hot Water Generation Mode. This parameter can be changed by the user or the installer. The temperature range of this parameter is 32° to 212°F. The default value is 185°F.

Reference page 18 for information regarding changing parameters.

Time - The time is displayed in the upper right-hand corner of the display. It is displayed in 24 hour format. Reference the night setback parameters on page 24 for information regarding adjusting the date and time.

Back button - Pressing this button will back the screen up to the previous screen.

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