Daikin EWAD740C-SS [173/304] Unit enable

ESIE10-01 Functional Control

Part 2 – Functional Description 2–25

2.2.1 Unit Enable

There are different ways to start and stop a unit. Enabling and disabling the chiller is accomplished

using set points and inputs to the chiller. The unit switch, remote switch input, and Unit Enable Set

Point all are required to be 'on' for the unit to be enabled when the control source is set to 'local'. The

same is true if the control source is set to 'network', with the additional requirement that the BMS

request must be 'on'.

Unit is enabled according to the following table.

Note: An "x" indicates that the value is ignored.

All these normal methods for disabling the chiller (no alarms) should cause a normal shutdown,

discussed later on, of any running circuits.

When the controller is powered up, the Unit Enable Set Point should be initialized to 'off' if the Unit

Status After Power Failure Set Point is set to 'off'.

Unit Switch

Control Source

Set Point

Remote

Switch Input

Unit Enable

Set Point

BMS

Request

Unit Enable

Off x x x x Off

x x x Off x Off

xxOffxxOff

On Local On On x On

xNetwork x x OffOff

On Network On On On On