DEHNrail modular, multipole

Pluggable four-pole surge arrester

Four-pole surge arrester consisting of a base part and plug-in protection module High discharge capacity due to heavy-duty zinc oxide varistor/spark gap combination Energy coordination with other arresters of the Red/Line product family Operating state/fault indication by indicator flag in the inspection window Easy replacement of protection modules without tools due to module locking system with module release button Nominal load currents up to 25 A Vibration and shock-tested in accordance with EN 60068-2


DEHNrail M 4P ...: Four-pole surge arrester consisting of a base part and plug-in protection module

DEHNrail M 4P ... FM: With remote signalling contact for monitoring device (floating changeover contact)


The four-pole, modular DEHNrail M 4P ... (FM) surge arresters were specifically developed for protecting three-phase industrial electronics terminal equipment. Adapted to this environment, the arresters with the new Red/Line design are designed for mounting on 35 mm DIN rails. The low voltage protection level and the comprehensive common and differential mode protection are characteristic of DEHNrail M 4P ... (FM). In order to optimally provide the low voltage protection levels for the terminal equipment to be protected, the device features input and output terminals for series connection. Therefore, DEHNrail M 4P ... (FM) devices ideally adapt themselves to the cable run upstream of the terminal equipment without requiring additional terminal blocks for outgoing cables. Compact in design, the DEHNrail M 4P ... (FM) already incorporates the tried and tested disconnector. It disconnects an overloaded arrester circuit from the power supply without interrupting the supply circuit.

The base part and protection module are coded to ensure against installing the incorrect module.

The new module locking system of the DEHNrail M family is unique for surge protective devices. It fixes the protection modules to the base part. Neither vibrations during transport nor the electrodynamic forces of discharge can loosen the connection.

In the event of the protective circuit, which is rated for high load currents up to 25 A, being overloaded despite of the powerful designs of the surge arrester, the protection modules can be easily replaced without tools by simply pressing the module release button.

Apart from the standard visual indication with green and red indicator flags, DEHNrail M 4P ... FM devices feature a three-pole remote signalling terminal. With its floating changeover contact, the remote signal can be used as a break or make contact according to the particular circuit concept.


Type DR M 4P 255 DR M 4P 255 FM
Part No. 953 400 953 405
SPD according to EN 61643-11 Type 3 Type 3
SPD according to 61643-1/-11 Class III Class III
Nominal a.c. voltage (UN) 230/400 V 230/400 V
Max. continuous operating a.c. voltage (UC) 255/440 V 255/440 V
Nominal load current a.c. (IL) 25 A 25 A
Nominal discharge current (8/20 µs) (In) 3 kA 3 kA
Total discharge current (8/20 µs) [L1+L2+L3+N-PE] (Itotal) 8 kA 8 kA
Combined impulse (UOC) 6 kV 6 kV
Combined impulse [L1+L2+L3+N-PE] (UOC total) 16 kV 16 kV
Voltage protection level [L-N] (UP) ≤ 1000 V ≤ 1000 V
Voltage protection level [L/N-PE] (UP) ≤ 1500 V ≤ 1500 V
Response time [L-N] (tA) ≤ 25 ns ≤ 25 ns
Response time [L/N-PE] (tA) ≤ 100 ns ≤ 100 ns
Max. mains-side overcurrent protection 25 A gL/gG or B 25 A 25 A gL/gG or B 25 A
Short-circuit withstand capability for mains-side overcurrent protection with 25 A gL/gG 6 kArms 6 kArms
Temporary overvoltage (TOV) [L-N] (UT) 335 V / 5 sec. 335 V / 5 sec.
Temporary overvoltage (TOV) [L/N-PE] (UT) 400 V / 5 sec. 400 V / 5 sec.
Temporary overvoltage (TOV) [N-PE] (UT) 1200 V / 200 ms 1200 V / 200 ms
TOV characteristic [L-N] withstand withstand
TOV characteristic [L/N-PE] withstand withstand
TOV characteristic [L+N-PE] safe safe
Operating temperature range (TU) -40°C...+80°C -40°C...+80°C
Operating state/fault indication green / red green / red
Number of ports 1 1
Cross-sectional area (min.) 0.5 mm2 solid/flexible 0.5 mm2 solid/flexible
Cross-sectional area (max.) 4 mm2 stranded/2.5 mm2 flexible 4 mm2 solid/2.5 mm2 flexible
For mounting on 35 mm DIN rails acc. to EN 60715 35 mm DIN rails acc. to EN 60715
Enclosure material thermoplastic, red, UL 94 V-0 thermoplastic, red, UL 94 V-0
Place of installation indoor installation indoor installation
Degree of protection IP 20 IP 20
Capacity 2 modules, DIN 43880 2 modules, DIN 43880
Approvals, Certifications KEMA, VDE, UL KEMA, VDE, UL
Type of remote signalling contact changeover contact
a.c. switching capacity 250 V/0.5 A
d.c. switching capacity 250 V/0.1 A; 125 V/0.2 A; 75 V/0.5 A
Cross-sectional area for remote signalling terminals max. 1.5 mm2 solid/flexible
Weight 138 g 141 g
GTIN 4.01E+12 4.01E+12
PU 1 pc(s) 1 pc(s)
Product Specifications (PDF) Product Specifications (PDF)