Home » Blog » Wiki » PPE (Personal Protective Equipment)

PPE (Personal Protective Equipment)

When I think of using PPE as a controls engineer, I think about electrical shock and arc-flash safety in working with electrical devices.

The PPE (Personal Protective Equipment) requirements to work on live electrical equipment is making doing commissioning, startup, and tuning of electrical control systems awkward and cumbersome. We are at a stage where the use of PPE is now required but practice has not caught up with the requirements. While many are resisting this change, it seems inevitable that we will need to wear proper PPE equipment when working on any control panel with exposed voltages of 50 volts or more.

With many electrical panels not labeled for shock and arc-flash hazard levels, the default PPE requires a full (Category 2+) suit in most cases, which is very awkward indeed. What can we do to allow us to work on live equipment in a safe manner that meets the now not so new requirements for shock and arc-flash safety?

Increasingly the thinking is to design our systems for shock and arc-flash safety. Typically low voltage (less than 50 volts), 120VAC, and 480 VAC power were often placed in the same control enclosure. While this is cost effective, it is now problematic when wanting to do work on even the low voltage area of the panel. The rules do not appear to allow distinguishing areas of a panel as safe, while another is unsafe. The entire panel is either one or the other. One could attempt to argue this point, but wouldn't it be better to just design our systems so that we are clearly on the side of compliance?

Here are my thoughts to improve electrical shock and arc flash safety by designing this safety into electrical control panels.

1. Keep the power components separate from the signal level components so that maintenance and other engineers can work on the equipment without such hazards being present. That's the principle. What are some ideas for putting this into practice?

2. Run as much as possible on 24VDC as possible. This would include the PLC's and most other panel devices. A separate panel would then house only these shock and arc-flash safe electrical components.

3. Power Supplies could be placed in a separate enclosure or included in the main (low voltage) panel but grouped together and protected separately so that there are no exposed conductors or terminals that can be reached with even a tool when the control panel door is opened.

4. Motor Controls running at anything over 50 volts should be contained in a separate enclosure. Try remoting the motor controls away from the power devices where possible. This includes putting the HIM (keypad) modules for a VFD (Variable Frequency Drive) for example on the outside of the control panel, so the panel does not have to be opened. Also, using the traditional MCC (Motor Control Centers) enclosures is looking increasing attractive to minimize the need for PPE equipment.

For example "finger safe" design does not meet the requirements for arc-flash safety. Also making voltage measurements to check for power is considered one of, if not the most hazardous activity as far as arc-flash goes.

Post a Comment:

Calculate (8 + 6) =

You may also like:

r/min: motor rotation speed unit, the number of revolutions per minute, also can be expressed in rpm. For example: 2-pole motor 50Hz 3000 r/min, 4-pole motor 50Hz 1500 r/min Conclusion: The motor rotation ...
The surge impedance loading (SIL) of a line is the power load at which the net reactive power is zero. So, if your transmission line wants to "absorb" reactive power, the SIL is the amount of reactive power ...
I have a generator of 3 hp, and it outputs 230 V, and I have a submersible Electric Pump, the motor of which is rated to operate at 460 V, Can I use a step up transformer to increase the voltage output from my ...
The rotating electrical machines have basically three noise sources: The ventilation system The rolling bearings Electromagnetic excitation Bearings in perfect conditions ...
My experience with the types of motors in electric vehicle is the following. There are three choices for motors in EVs, permanent magnet PM, integral permanent magnet IPM, and induction motor IM. They each ...
Gozuk Service Gozuk Blog: all about electric motor control & drives industries development in energy saving applications.


Like pumps, fans consume significant electrical energy while serving several applications. In many plants, the VFDs (variable ... energy consumedA frequency inverter controls AC motor speed. The frequency inverter converts the fixed supply frequency (60 Hz) to a ... Motor starter (also known as soft starter, motor soft starter) is a electronic device integrates soft start, soft stop, ... Soft starter allows the output voltage decreases gradually to achieve soft stop, in order to protect the equipment. Such as the ... Soft Starter reduces electric motor starting current to 2-4 times during motor start up, reduces the impact to power grid during ...

In Discussion