The TECNA 9347AX is an ATEX-certified retractor tool balancer for tools weighing 8.8-13.2 lb, built for use in areas where a flammable gas atmosphere may be present. It carries the marking II 2G Ex h IIB T6 Gb.

Cable travel is 8.2 ft (2,500 mm) and capacity is adjustable across 8.8-13.2 lb (4-6 kg). It is a retractor, so the tool returns to its rest position when you let go rather than staying where you leave it.

What the marking means:

• II - for surface industry, not mining
• 2G - category 2, gas. Suitable for Zone 1, and by extension Zone 2. Not Zone 0
• Ex h - protection by constructional safety, to EN ISO 80079-37 for non-electrical equipment
• IIB - the gas group, the middle of the three groups
• T6 - temperature class, the most demanding of the six
• Gb - equipment protection level: no effective ignition source in normal operation or expected malfunction

The gas group is the part that decides whether this model will do. Group IIB covers the group IIA gases and adds di-ethyl ether, ethylene, ethanol, methyl ethyl ketone and n-propyl alcohol. It does not cover acetylene or hydrogen - those need a IIC model, which in this range means one of the lighter capacities.

The balancer must be grounded at installation.

The balancer is intended to be used indoors, at 41 to 140 F (5 to 60 C). Outside that range there will be premature deterioration of the unit or its components. If it will meet chemically aggressive gas, liquid or powder, confirm compatibility with us before ordering.

Four things that are easy to get wrong:

• The tool you hang on it must itself be ATEX certified to a hazard class equal to or higher than the balancer. An ATEX balancer does not make a non-ATEX tool acceptable
• Static electricity carried on people can be an ignition source. Ground every conductive object, not just the balancer
• Do not let the snap hook strike other metal nearby. That can throw a mechanical spark
• Do not use the balancer if it is visibly damaged. Unintended friction is an ignition risk in its own right

This is a gas-rated balancer only. It must not be used where a potentially explosive dust atmosphere may be present. If you are working around combustible dust, the ATEX zero-gravity balancers are the ones that add the II 2D dust marking - ask us and we will point you at the right model.

This series has something the 9336AX-9340AX range does not: a mechanism that locks the cable so you can work with no upward pull on the tool at all - reaching inside a vehicle body, for instance. It engages when you let the tool rise slowly. To release it, pull the tool down slightly and let it rise quickly. That is worth knowing, because a balancer that appears to be jamming is usually just the lock doing its job. It can also be disabled permanently if you would rather not have it.

Specifications:

• Capacity: 8.8-13.2 lb (4-6 kg), adjustable
• Cable travel: 8.2 ft (2,500 mm)
• ATEX marking: II 2G Ex h IIB T6 Gb
• Ambient temperature: 41 to 140 F (5 to 60 C) - indoor use only
• Unit weight: 7.32 lb (3.32 kg)
• Stainless steel cable
• Rugged cast aluminium body
• Entirely conductive, grounded, spark-proof materials
• Adjustable capacity
• Safety suspension
• Safety device against load dropping due to spring breakage
• Cable locking mechanism, can be disabled
• Adjustable stroke limiting device
• Cable guide in antifriction material
• Inert spring drum assembly
• Polyamide thimble

Two things to get right on site. The structure you hang it from has to be stronger than five times the balancer weight plus the maximum load - and if several balancers share one structure, five times the total of all of them, each on its own independent connection point. And at every service, check the ground cable and the tightness of that marked screw, and clear away dust - no more than 5 mm of buildup.

Every production lot is sample-tested: a static test at 1.25 times the maximum rated load held for ten minutes at full stroke, to DIN 15112, and a dynamic test at 1.1 times maximum load run for an hour.

Other capacities in the 9346LAX-9350AX series: 9346LAX (1.1-4.4 lb, IIC), 9346AX (4.4-8.8 lb, IIC), 9348AX (13.2-17.6 lb, IIB), 9349AX (17.6-22 lb, IIB), 9350AX (22-31 lb, IIA).

Do not need the cable lock? The TECNA 9337AX is this same balancer without it - identical capacity and stroke.

Not working in a hazardous area? The TECNA 9347 is the same retractor without the ATEX certification, at the same capacity and stroke. And if you need the load to stay where you leave it rather than return to rest, that is a zero-gravity balancer, not a retractor.

TECNA's guide to the ATEX gas classification system - what each element of the marking means, and which zones and explosion groups it covers. The model summary in the diagram is generalised and does not match TECNA's per-model tables in every case; the marking that applies to this balancer is II 2G Ex h IIB T6 Gb, as listed in the specifications above.

Supported in the USA by Tool Balancers USA.