3 Phase 4 Wire Three Phase Voltage Monitoring Relay Over Under
Voltage Protection
♦ Features
-- Compact modular size
-- Neutral loss
-- Three-phase Four-wire monitoring of phase sequence, phase loss,
over- and undervoltage and phase unbalance
-- Powered by the measuring circuit
-- 1CO & 1NC contacts
-- 5 LEDs for status indication
♦ Functions
Protection the Phase sequence,Phase Loss,Phase unbalance,
Over/Under Voltage and NEUTRAL Loss to protect the
equipment(Pump ,Elevator Control Pannel,Blowers,Pumps) from
broken
♦ Typical Applications
• Pumps • Fans
• Blowers • Motors
• Compressors
♦ Approvals
• CE • CCC
♦ Technical data
Type | JVRD-380N |
Measuring circuit | L1,L2,L3,N |
Rated voltage | 220VAC,380VAC ,440VAC 460VAV,480VAC,50/60Hz |
Monitoring functions | phase sequence, phase loss, overvolatege, undervoltage, phase
unbalance |
Voltage setting range | Type suffix | Overvoltage | Undervoltage | blank | +15% | -15% | A | +10% | -10% | B | +12.5% | -10% | C | +15% | -12.5% | T | customized |
|
Indicators | phase sequence, phase loss, overvolatege, undervoltage, and normal |
Output contacts | 1CO & 1NC |
Contact capacity | 6A ,250VAC |
Dimensions (H x W x D) | 79×23×79mm |
Mounting | DIN rail |
What is 3 Phase 4 Wire?
Three-phase four-wire system, in the low-voltage distribution
network, the transmission line generally adopts three-phase
four-wire system, three of which represent A, B, C three-phase, and
the other is neutral N or PEN (if the loop power supply) When the
neutral point of the side is grounded, the neutral line is also
called the zero line (old-fashioned name, which should be gradually
avoided, renamed PEN. If it is not grounded, the neutral line
cannot be called the neutral line in a strict sense).
In the single-phase transmission line entering the user, there are
two lines, one is called the phase line L, and the other is called
the neutral line N. The middle line normally passes the current to
form the current in the single-phase line. In the system, when the
three-phase is balanced, the neutral line (zero line) is
currentless, so it is called three-phase four-wire system; in the
380V low-voltage distribution network, in order to obtain the 220V
phase voltage from the 380V line voltage, the N line is set. Some
occasions can also be used for zero-sequence current detection for
monitoring the three-phase power balance.
![](http://img.everychina.com/nimg/0e/dc/8cd149d3c282b675b5c2ae50ae0d.jpg)