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Analogue Process Control Services a division of NESS Corporation
Voltage Presence Relay - VPR271
Drawings
Data Sheet; Voltage Presence Relay
Inputs
ac Voltage
Signal Powered
Functions
ac Transducer
Alarm
Output
Relays
The VPR271 provides an economical and compact solution to monitoring of 3-phase voltage up to 700V phase to phase with two
relay outputs indicating;
- Loss of three phases
- Loss of one phase.
The 3-phase voltage plus neutral can be directly connected to the VPR271 as long as the maximum phase-to-phase voltage does not exceed 700V. To use the VPR271 with higher voltages, a step down transformers (PT) must be used.
Neutral must be connected for proper operation. Due to its total width of only 22.5 mm and using the 35mm Din-Rail mounting arrangement, the VPR271 is ideal for "nestmounting" in field enclosures or as a "space saver" in control
cabinets. The VPR271 is signal powered from the incoming AC-voltage.
Function
- With any phase present the internal step down DC/DC converter will energise relay 1.
- Each phase is monitored by a trip circuit providing LED indication of phase presence and de-energizing relay 2 if any one of the three phases fail.
- If all three phases are present then both relay 1 and relay 2 are energised.
