GDV-20-385-3+1 FM AC Power Surge Protective Device, 3+1 Configuration, 20 kA Imax

Description

The GDV-20-385-3+1 FM is a Class II surge protective device (SPD) designed for lightning overvoltage protection of three-phase AC power supplies. It uses a 3+1 configuration, providing protection between line and neutral (L-N) and between neutral and protective earth (N-PE). The device is intended for installation on a 35 mm DIN rail and includes status indication plus a remote signalling contact.

Product Overview

The GDV-20-385-3+1 FM is an AC power surge protective device classified as SPD Type II. It is rated for a nominal operating voltage Un of 220V~ and supports a maximum continuous AC operating voltage Uc of 385V~ for the L-N path and 255V~ for the N-PE path. The nominal discharge current In is 10 kA, and the maximum discharge current Imax is 20 kA.

Voltage protection levels are ≤1.2 kV for the L-N path and ≤1.0 kV for the N-PE path, measured at In with an 8/20 µs waveform. Response times are 25 ns for L-N and 100 ns for N-PE. A status indicator shows green for normal operation and red for failure, and a changeover remote signalling contact is provided for status monitoring.

Key Features

• Class II (Type II) surge protective device for three-phase AC power supplies
• 3+1 configuration with L-N and N-PE protection paths
• Nominal discharge current In: 10 kA; maximum discharge current Imax: 20 kA
• L-N voltage protection level Up: ≤1.2 kV; N-PE Up: ≤1.0 kV at In (8/20 µs)
• Response time: 25 ns (L-N), 100 ns (N-PE)
• Status indication: green for normal, red for failure
• Remote signalling changeover contact rated 250V/0.5A AC and 125V/0.2A DC
• 35 mm DIN rail mounting
• Housing material PC+ABS with UL94-V0 flame rating
• IP20 enclosure protection

Technical Specifications

Parameter	Value
Model	GDV-20/385/3+1 FM
SPD classification	II
Nominal operating voltage Un	220V~
L-N maximum continuous AC operating voltage Uc	385V~
N-PE maximum continuous AC operating voltage Uc	255V~
Nominal discharge current In	10kA
Maximum discharge current Imax	20kA
L-N voltage protection level Up (In@8/20µs)	≤1.2kV
N-PE voltage protection level Up (In@8/20µs)	≤1.0kV
L-N response time tA	25ns
N-PE response time tA	100ns
L-N, N-PE status indication	Green: normal / Red: failed
Mounting method	35mm DIN rail
Conductor connection capacity	≤25mm²
Maximum torque	3.2Nm~3.7Nm
Housing material	PC+ABS
Housing material flame rating	UL94-V0
Remote signalling contact type	Changeover contact
Remote signalling contact AC performance	250V/0.5A
Remote signalling contact DC performance	125V/0.2A
Enclosure protection rating	IP20
Temperature (humidity) range	-40℃ to +80℃, relative humidity ≤95%
Altitude	≤3000m
Main body dimensions	90mm×65.3mm×72mm (tolerance ±1 mm)

Applications

The GDV-20-385-3+1 FM is used for Class II lightning overvoltage protection of three-phase AC power supplies. It is suitable for installation at distribution points where three-phase AC power requires surge protection with L-N and N-PE paths.

Installation and Use

• The device may be connected in direct parallel wiring as shown in the wiring diagram. For better protection, keep the wiring as short as possible, with total length controlled within 0.5 m.
• Connection conductors should be multi-core copper conductors of 6 mm² or larger.
• A suitable circuit breaker or fuse should be connected in series ahead of the device. For circuit breakers, use C trip characteristic.
• Power must be disconnected during installation. Live operation is strictly prohibited, and connecting conductors must meet the requirements.
• During normal operation, the status indicator should be green.
• The device requires no special maintenance; periodically check whether the module is loose and whether the status indication is normal.
• The device is considered failed and should be replaced promptly if either of the following occurs: the status indicator turns red, or the alarm dry contact changes to an open-circuit state.

Frequently Asked Questions

What does the status indicator mean?

Green indicates normal operation. Red indicates that the device has failed and should be replaced.

How is the device mounted?

It is mounted on a 35 mm DIN rail.

What conductor size is recommended?

Use multi-core copper conductors of 6 mm² or larger. The device accepts conductors up to 25 mm².

How can failure be detected remotely?

The remote signalling changeover contact can be used for monitoring. A change to the open-circuit state indicates failure.