Mounting/grounding recommendations

The HUBER+SUHNER lightning/EMP protector product range offers high flexibility to meet mounting and grounding requirements in the field. Basically all mounting options are simultaneously suitable for grounding purposes.

Our comprehensive portfolio includes:

Bulkhead mounting

• protection zone principle
• lowest contact resistance
• corrosion-resistant contact zone
• waterproof wall sealing
• RF leak-proofness
• vibration resistance

Bulkhead mounting is highly recommend.

Screw mounting

For best protection when establishing protection zones consequently in accordance to IEC 62305, it is recommended to deploy bulkhead mounting facilities. Thus the protectors can be installed as wall feed-through directly in the wall of the protected room. Doing so, the protectors should be installed consequently with the surge down conducting part – stub or gas discharge tube – outside of the protected area in order to not cause any unnecessary interferences when dissipating surges (this is reflected by the recommendations and definitions for "unprotected and protected side" of the component tables. Bulkhead mounting types and all high-pass filter types are marked accordingly).

The special HUBER+SUHNER bulkhead fixation design automatically enables a good long-term performance concerning a waterproof bulkhead transition, a corrosion-resistant (gas-tight) contact area resulting in a stable contact to the bulkhead ground-plane, a low transition resistance and a vibration-resistant mounting of the protector (assuming the right sufficient torque forces are applied as shown in the supplied assembly instructions).

This is true for standard sheet metal bulkheads such as stainless steel, copper or chrome-plated aluminium with standard surface roughness and mounting holes according to the related product mounting hole specification.

For other mounting solutions care has to be taken for minimum interference. Generally, all mounting options can carry the specified surge current when properly installed.

Grounding/Bonding Rules

For a good grounding respectively bonding the following has to be considered:

• During installation, the lightning protection components must be connected with the central grounding point of the equipment (central grounding bar) in a low-resistance and low-inductance way. Inadequate grounding concepts with ground loops, insufficiently sized grounding cables (smaller than 16 mm²/AWG 6), poor connections, etc., will increase the residual energy behind the lightning protector as a result of high impedance (ohmic resistance by length and size and in addition inductance by length).
• The contact points of the ground connection must offer good electrical conductivity (contact points must be bare and free from dirt, dust and moisture).
• When threaded contacts are tightened (bulkhead grounding, capsule holder), the minimum torque specified by the manufacturer must be observed in order to minimise the contact resistance and to establish the effects mentioned above.
• The lightning protection components should wherever possible be located in the unprotected zone in order to rule out inductive interference.
• HUBER+SUHNER lightning protection components are characterised by their quick, easy, and at the same time reliable installation methods. The preferred variant is single-hole mounting as wall feed-through. They can be applied with round or with D- or H-shaped mounting holes to prevent rotation. The mounting hole size is matched to the connector size and thereby to the forces acting on the component.

All this is crucial for achieving the lowest possible residual surge pulse (voltage and energy) on the protected side and with it keeping the interference load for the equipment as low as possible.

All HUBER+SUHNER lightning protection components are supplied along with an installation instruction describing the proper installation procedure.