Application envelope

Introduction

The IQ products CSV, CM-RC-01, CM-RC-02, CM-SW-01 and SE-i1 are featured by an application envelope (= application limits) protection function. It protects the compressor against excessive operating conditions, but allows also to receive warnings via Modbus when coming close to the individual limits. When taking the warnings into consideration, the superior system controller can take countermeasures and thus avoid a compressor stop.

Exemplary application envelope with legend

Overview of relevant Modbus registers

Register	Name	Description	Type
12005 (I)	Envelope status	Status of the application envelope protection 0 = Compressor stopped 1 = Compressor starting (envelope protection deactivated for 120 s) 2 = Compressor running within limit (within green dashed line) 3 = Compressor stopping (envelope protection deactivated) 4 = Envelope warning is active 5 = Envelope critical is active 6 = Envelope fault is active 8 = Critical alarm "30-12 Envelope: Compressor would be stopped if faults were enabled" is active 10 = Monitoring deactivated	uint8
12006 (I)	Envelope zone	Zone in which the compressor is currently operating — or, if a fault is active, in which zone the operating point was when the fault was set. 0 = Inside application envelope (within green dashed line) 1 = Low evaporation, low condensation 2 = Low evaporation 3 = Low evaporation, high condensation / high pressure 4 = High condensation / high pressure 5 = High evaporation, high condensation / high pressure 6 = High evaporation 7 = High evaporation, low condensation 8 = Low condensation 10 = Monitoring deactivated	uint8

Application envelope zonesSST: Saturated suction temperature = evaporating temperatureSDT: Saturated discharge temperature = condensing temperature — Application envelope zones
SST: Saturated suction temperature = evaporating temperature
SDT: Saturated discharge temperature = condensing temperature