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Thiim PMSA RMS Voltage Monitoring Relay


  • Multi-range 50…830V for use in Single phase, Two-phase or Three-phase systems with or without Neutral and Ground
  • True RMS voltage measurement
  • Measures Neutral to Ground voltage and 3 x Phase to Phase or 3 x Phase to Neutral
  • Over and Under voltage monitoring with individual relays or window function with 2 C/O contacts
  • One Relay can be dedicated to the Neutral to Ground monitoring
  • Easy set-up by keying in actual parameters
  • Time delay - On and Off - can be set individually
  • Latched Relay function can be selected
  • LEDs indicate the status of the relay, latch, timing and display information
  • Extremely compact and low power consumption


The RMS voltage monitoring relay PMSA is a universal 2, 3, 4 and 5 wire Multi-voltage unit that measures under as well as over voltages in star or delta configuration. The PMSA is designed to fulfill the demand for one unit for all applications in order to reduce overall costs. The PMSA is build with a strong MCU that can handle 40000 13bit voltage samples/sec for a precise and true RMS conversion.

The two internal relays can be used for Phase and Neutral to Ground voltage measurements, or one relay can be used for Phase measurements and the other relay dedicated for Neutral to Ground measurement.

Application Generally where humans and equipment have to be protected against unexpected voltages caused by broken wires - especially the Neutral - or voltages that are not within acceptable limits for the connected equipment.

  • AC voltage 45…66Hz
  • Range - Connection type 1-3 50…480V N-Phase
  • Range - Connection type 4-5 86…830V Phase-Phase
  • Input resistance N-L1, N-L2, N-L3, N-PE 1Mohm
  • Supply Range 18…288VAC, 20…400VDC
  • Fuse Internal 400mA in A1
  • Breaking capacity 100A / 250Vdc/ac
  • Power consumption Max 4W
  • RELAY 2 C/O or 2 x 1 C/O for separate Over & Under voltage monitoring or 1 C/O dedicated for Neutral to Ground monitoring
  • Contact rating 6A, 250VAC, 1500W, AgNi
  • Mechanical life 30 million operations

Additional Information

Manufacturer Thiim
Product Name / Options Price (ex VAT)
Thiim PMSA-PA4C RMS Voltage Relay 18 - 288 VAC, 20-400 VDC - 41889 Call for Prices