Edition 52
June 2011

Battery Handling Precautions

The Kentec range of control panels and power supplies are designed and certified in accordance with EN54-4 requirements.
In order to comply with EN54-4 the power supplies must have a main power source and a secondary power source in the event of a main supply failure. This secondary power source is provided by a pair of 12 volt Valve Regulated Lead Acid batteries (VRLA), wired in series.

These batteries can present some hazards, however these are minimised by taking sensible precautions and care when handing the batteries and working near the batteries.

Label Information
Typical VRLA battery labelling gives warnings that the batteries contain lead, they should not be charged in a sealed container, care should be taken to avoid shorting the terminals and units should be recycled and must not disposed of in domestic waste. 

Electrical Energy
Accidental short circuit of the battery terminals by a conductive object, such as a metal tool or item of jewellery etc. may generate sufficient heat to cause severe burns, create arcing or cause a metal object to melt and splash molten material.

It is recommended that before working with batteries, metal objects should be removed – including rings, bracelets, watches and necklaces. Alternatively, these units should be adequately covered by an insulating layer (gloves for example) to avoid an accidental short circuit.

Never place metal tools near to, or on top of the battery

Batteries are supplied with packaging insulators fitted on the terminals. These should be left in place until the charger cables are to be installed, to further reduce the risk of accidental shorting of the battery terminals.

Emission of Gases
Hydrogen and Oxygen are both evolved during the battery charging process. Hydrogen gas can be explosive at levels above 4% and therefore it is important that the batteries are not charged in a fully sealed container.
The Kentec control panels have IP30 ingress protection, which ensures adequate ventilation for these gases to disperse.
Caution needs to be observed if the control panel is installed in an enclosure which has a very high IP rating.

The batteries contain lead and can be heavy for larger capacity batteries. They can also be awkward to handle and this may result in possible strains to the body as well as the possible risk of dropping the battery.
Always use correct lifting procedures to minimise strain to the human body and use lifting handles or ledges (if provided) to reduce the risk of dropping the battery.

Damaged Batteries
No attempt should ever be made to repair a damaged battery.

Kentec Warning Signs – Product Update

The Kentec warning signs have recently undergone a revision to their design and are now supplied with the PCB reference D1101 Issue 6.

This version of the product now has the facility to illuminate just the top half of the display or just the lower half independently. This configuration and operation is given on Page 5 of the Warning Sign product manual (Man1139 issue 2)

Both issue 5 and issue 6 circuit boards have a revised input operating voltage of 15-30 volts. This lower input voltage was increased from the original 9 volt specification in order to prevent problems when controlling the sign from a reverse voltage monitored circuit.

Some customers observed that when driving the sign from a monitored circuit the sign would illuminate in the “de-energised” monitoring polarity and therefore it became necessary to increase the minimum input voltage to prevent this.

However, unfortunately this does mean that these units are no longer suitable to be directly powered from 12 volt control systems.

Download the current warning sign manual

Download the Warning Sign datasheet


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