Loadcells can be supplied with a cable that is permanently attached or a chassis type connector mounted on the loadcell that allows a removable cable fitted with a connector to be used.

Loadcells with a permanent cable have the advantages of low cost, increased reliability and simplicity when compared to a connector version.

The advantages of a loadcell with a chassis connector are:

• Ease of assembly if the loadcell is screwed into position or fitted in an awkward position.
• Rapid repair in the event of damage to the interconnecting cable.
• Cables can be removed during extended dormant periods, reducing risk of damage.
• Ease of transfer if the loadcell is used in several different applications.
• Varying interconnection leads for use with different instrumentation.
• Easier disassembly if regularly packed away as part of a portable test setup.

Some of our loadcells offer a chassis mounted connector option as standard. We are able to fit connectors to customers specifications on most of our loadcells. We have experience of the following manufacturers: Binder, Lemo, Bulgin, Deutsch, Jaeger, AB, Amphenol, Tyco and many others.

Specifying the Loadcell Cable Type

Our standard PVC sheathed screened cable is an economic cable solution suitable for most applications. However over the years applications have driven the cable specification to many extremes and our clients often now need precise dimensional information to facilitate design. The following prompt list, when read in conjunction with our cable type specification table, will enable the choice of the optimum cable solution. Our engineering department are pleased to assist you with your evaluation.

Cable Specifier Prompt List

1. Length

Most cable lengths are possible, we recommend the supplied, or ‘as calibrated’ cable length is retained as lengthening or shortening the cable will affect the loadcell sensitivity. See Engineering Sheet E012 for details. Voltage sensing obviates the errors created by long cable lengths above 10m and is available using a 6-core cable with suitable instrumentation.

2. Routing, Strain and Travel

Our table below provides data for minimum bend radius, overall diameter, and chemical and heat resistance.

Ideally loadcell cable travel should be minimal and in repetitive production environments should be achieved by using a purpose made retractable cable (curly cable). Where cables are required to flex great care should be taken to evenly distribute the cable deflection over the maximum length possible.

Abrasion of the cable sheath should be avoided using a protective conduit or sleeve.

Tight kinks should be removed by using strain relief measures such as cable wraps or sleeves.

If dynamic tight kinking of cables is unavoidable the service life may be extended by choosing cable with a suitable insulation material and a high number of conductor strands.

3. Self Weight

In high acceleration applications it may be prudent to specify a lightweight cable to reduce accelerative force induced strain.

4. Sealing and Fluid Contact

Standard PVC cables can be sealed into a loadcell maintaining a rating of IP67 with no problems but in extreme environments and extended submersion it is recommended that a more suitable cable be used. Our Raychem cable is a good choice for many reasons. It has a tough solid cast neoprene jacket with a very round form, ideal for good sealing in a compressive gland and is resistant to mechanical damage and resultant fluid ‘wicking’. It is mineral oil and chemical resistant and also offers good adhesion to the resins used in some IP68 sealing applications.

High temperature PTFE cables offer poor sealing. The irregular form, vulnerable wrapped construction and inherently slippery jacket all cause problems. In some applications, PTFE cable can be sealed adequately by enclosing the whole cable in a heatshrink jacket. PTFE insulated cables are not very durable for cyclic motion applications.

Although PVC cable is perfectly adequate for most applications, there are limitations. Very low temperatures can cause brittleness and if the cable is flexed it may crack. Mineral oils and chemicals can cause deterioration of the jacket and insulation. If the standard PVC cable is not appropriate for an application, alternatives can usually be fitted. High temperature, oil resistant, chemical resistant and retractable (curly) cables are all stocked.

Please contact our engineering department for more information, technical assistance and prices.

Standard Loadcell Cables

Special Loadcell Cable Options

Notes: Care should be taken in the handling or use of PVC cables when operating below 0°C. For highly mobile applications in sub-zero conditions, please consult our engineering department.