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5.5.6 Master/slave mode – defrost synchronisation via wiring
All controller types versions >= V4.00
Requirements
External wiring on hardware side; for details, see chapter Wiring of the master-slave function for defrost
synchronization.
Setting of the DIP switch S3, coding switch 4 must be set to ON;fordetails,seechapterSetting of the
controller type and master/slave mode.
Function Description
The master/slave function is used for refrigerated cases when the operation of several evaporators, without
additional protective measures can result in the reciprocal icing of the evaporators (all controller types except
UA131DD).
This problem is prevented due to the defrost synchronisation in master/slave operation. All refrigerated cases
and case zones defrost simultaneously and then switch to cooling together. Multiple participating controllers are
synchronised via hardware wiring, see chapterWiring of the master-slave function for defrost synchronization.
In addition, in the case of one controller in two-zone operation, this can be used to force the joint return of both
zones to cooling following a defrost.
Damage to the installation and stock loss!Whenusingthisfunction,itmustbeensuredthat
incorrect parametrisation does not result in simultaneous defrost and cooling of the synchronised
refrigeration points.
This function requires additional external wiring for multiple participating controllers. It must be
ensured for the wiring of master and slave case controllers that the power supply is only implemented
with one phase (e.g. only via L1).