Product category:
Machine Safety Components
News Release from: Grace Engineered Products | Subject: GEP voltage indicators
Edited by the Engineeringtalk Editorial
Team on 11 February 2008
Voltage indicators boost paper mill
safety
A voltage indicator is a permanently wired 'voltmeter' that provides electricians with a full-time, visual, independent, thru-door power indication.
Near-death experiences among paper mill electricians are all too common, prompting one paper mill to use voltage indicators (VIs) to enhance its electrical safety programme Electrical safety boils down to a single question: "voltage or no voltage?"
This article was originally published on Engineeringtalk on 6 Apr 2006 at 8.00am (UK)
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Electricians rely on a voltmeter to provide the right answer and there is no room for error.
Wiring a VI to the primary power source provides an answer to the voltage question.
This pushbutton-sized device is a permanently wired 'voltmeter' that provides electricians with a full-time, visual, independent, thru-door power indication.
Further reading
External control panel saves time
Control panel combines external and internal control panel receptacle to increase safety and save time by making the test-reset functions available to maintenance staff from outside the control panel.
Voltage detector enables safer maintenance
ChekVolt, now C-UL listed, allows for NEMA 12/4/4X installations and is designed to increase electrical safety by diminishing the risk of arc flash.
A VI serves has a single purpose: to indicate the presence of hazardous voltage.
In the past, the mill used neon pilot lights installed on electrical mains.
A neon indicator's intensity provided limited indication of voltage levels and this simple 'voltage indicator' still needed fuses and replacement bulbs.
After seeing the safety benefits of thru-door voltage indicators, the paper mill built a neon indicating light assembly with access holes that electricians used to verify zero energy after opening the disconnect.
They installed these on 208V lighting panels.
A single 30mm pushbutton-sized VI overcame the limitations of the neon pilot light assembly.
This three-phase device operates at 40-750V AC or 30-1000V DC, requires no fuses, uses long-life LEDs, redundant circuitry and potted construction for high reliability.
In addition, it was low cost and very easy to install.
The mill maintenance manager began installing a few units into high-maintenance areas of the plant.
As the days went on, the mill maintenance staff began to see the benefits of this simple, reliable device and started installing them throughout the plant.
Increasingly stringent safety requirements demanded by OSHA forced the mill to add a voltage verification step to its mechanical lock-out tag-out procedure (LOTO).
Mechanics needed to have an electrician verify a 'zero voltage' state on the load side of their circuit breaker disconnects before performing equipment maintenance.
This added work and downtime would increase costs of the paper mill's scheduled shutdowns.
The solution was to use a thru door VI as a substitute "electrician" for this zero voltage checking step.
Operating the isolator and seeing a real voltage feedback from a VI provides a secondary indication that the electrical energy has been pre-verified as isolated.
Moreover, for a critical failure to occur both devices would have to fail at the same time.
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