Backup Mode

Description

The synchronization ports of two cooling units with the same commercial reference are connected in parallel.

One cooling unit is the main cooling unit, the other is the backup cooling unit.

Normally the main cooling unit is operative, and the backup cooling unit is in standby.

When the main cooling unit goes in Pb1 error or High temperature alarm (HAL), it permanently closes the synchronization output and makes the backup cooling unit operative. The main cooling unit behavior depends on the alarm type as follows:

Alarm type on main cooling unit	Main synchronization output	Main cooling unit	Backup cooling unit
Pb1 error	Closed	Standby	Operative
External alarm	Open	Standby	Standby
High temperature alarm	Closed	Operative	Operative
Low temperature alarm	Open	Operative	Standby
No alarm	Open	Operative	Standby

When the Pb1 error or High temperature alarm (HAL) condition terminates, the main cooling unit releases the synchronization output to make the backup cooling unit go back into standby.

Low temperature alarm (LAL) is managed as a No alarm condition.

Setting Procedure

Enter the Programming menu:

Press and hold SET for at least 5 seconds .
Scroll to PA1. Press SET to enter PA1 password using the keys and . Press SET to confirm.

Set the main cooling unit:

Scroll to H11 and press SET
Change value to +14 using the keys and . Press SET to confirm.

Set the backup cooling unit:

Scroll to H11 and press SET
Change value to -14 using the keys and . Press SET to confirm.

The changes made to the parameters are taken into account after powering Off and On the cooling units.