DEHNbloc Maxi

Coordinated Lightning Current Arrester

For protecting low voltage consumer’s installations against surges and even direct lightning strikes. For installation in conformity with the lightning protection zone concept at the boundaries from 0A– 1.
  • Encapsulated RADAX Flow spark gap with high follow current limitation
  • No tripping of 32 A gG fuses up to short-circuit currents of 50 kArms
  • High lightning current discharge capacity
  • Directly coordinated with DEHNguard ... and V(A) NH ... surge protective devices without additional cable length
  • NH00 design
  • Low voltage protection level


DBM NH00 255: Coordinated single-pole lightning current arrester in NH00 design with high follow current limitation for UC = 255 V


The coordinated DEHNbloc Maxi ... lightning current arresters adapt themselves to every kind of application. Whether being used in an exposed position or in harsh industrial environments: DEHNbloc Maxi ... always offers the right solution. The single-pole devices are coordinated with the proven DEHNguard and V(A) NH surge arresters of the Red/Line family. Irrespective of cable lengths and without requiring additional decoupling coils, the surge protection concept can be adapted individually to the special conditions of the installation.

DEHNbloc Maxi arresters provide the patented encapsulated creepage discharge spark gap and RADAX Flow follow current limitation. This means that special safety distances from busbars or other equipment are not required and backup fuses are not tripped due to the lacking selectivity between the protective device and any overcurrent protection system, thus ensuring maximum system availability.

DEHNbloc Maxi NH00 255 was specifically designed for industrial distribution boards and supply systems and allows compact and space-saving installation in NH00 fuse holders or disconnectors depending on the particular system.


DEHNbloc Maxi NH00 255

DEHNbloc Maxi NH00 255

Basic circuit diagram DBM NH00 255Dimension drawing DBM NH00 255

Coordinated single-pole lightning current arrester in NH00 design for TN-C and TN-S systems with a nominal voltage of 230 / 400 V.


Part No.
SPD according to EN 61643-11 / IEC 61643-11
Nominal voltage (a.c.) (UN)
Max. continuous operating voltage (a.c.) (UC)
Lightning impulse current (10/350 µs) (Iimp)
Specific energy (W/R)
Voltage protection level (UP)
Follow current extinguishing capability (a.c.) (Ifi)
Follow current limitation / Selectivity
Response time (tA)
Max. backup fuse (L) up to IK = 50 kArms
Temporary overvoltage (TOV) (UT) – Characteristic
Operating temperature range (parallel connection) (TUP)
Number of ports
For mounting on
Enclosure material
Place of installation
Degree of protection
Extended technical data:
– Max. prospective short-circuit current
– Limitation / Extinction of mains follow currents
– Max. backup fuse (L) up to IK = 100 kArms
Part No.
  • DBM NH00 255
  • 900 255
  • type 1 / class I
  • 230 V (50 / 60 Hz)
  • 255 V (50 / 60 Hz)
  • 25 kA
  • 156.25 kJ/ohms
  • ≤ 2.5 kV
  • 50 kArms
  • no tripping of a 32 A gG fuse up to 50 kArms (prosp.)
  • ≤ 100 ns
  • 315 A gG
  • 440 V / 120 min. – withstand
  • -40 °C ... +80 °C
  • 1
  • NH fuse holders of size NH00
  • thermoplastic, red, UL 94 V-0
  • indoor installation
  • according to installation situation
  • Use in switchgear installations with prospective short-circuit currents of more than 50 kArms (tested by the German VDE)
  • 100 kArms (220 kApeak)
  • up to 100 kArms (220 kApeak)
  • 315 A gG
  • 194 g
  • 4013364125773
  • 1 pc(s)
  • 900 255
  • Specifications (PDF)
  • More
    • Further Pictures
      Basic circuit diagram DBM NH00 255
      open PDF
      Dimension drawing DBM NH00 255
      open PDF
      Further Information
      Product Specifications (Text)


      Coordinated DEHNbloc Maxi NH00 255 lightning current arrester
      Coordinated single-pole lightning current arrester 
      in NH 00 design with high follow current limitation
      Type 1 SPD according to EN 61643-11
      RADAX Flow spark gap technology 
      for follow current limitation
      Max. continuous operating voltage: 255 V a.c.
      Voltage protection level:	<= 2.5 kV 
      Lightning impulse current (10/350): 25 kA
      Follow current extinguishing capability: up to 100 kArms
      Energy-coordinated with arresters of the 
      Red/Line series according to IEC 62305-4

      delivery and installation.

      Brand: DEHN
      Type: DBM NH00 255
      Part No.: 900 255

      or equivalent.
      Installation Instructions
      CAD-Data for registered Users