Thread: Festool Rotex 150-slight electrical shocks

Originally Posted by jimj

but it would appear that I could really get a zap that could prove harmful without the safety box tripping.

Yep it is possible, but as you say, if you keep yourself and the tool (especially) dry then you will minimise any chance of that happening.

Also, ALWAYS use the safety box, as the type of electrocution that it DOES protect you against is generally much more likely to happen, than the one I described.

Jim,
thanks for the kind words. On discussing your problem with some colleagues, another alternative protective measure was suggested: rubber gloves. It sounds weird, (& kind of kinky) but a washing-up glove worn on your right (i.e. body-gripping) hand will be effective insulation, and if undamaged will provide effective insulation for currents <30mA. But it won't be comfortable! Knee pads alone won't isolate you sufficiently for protection. All you need do is to nudge a steel railing or balustrade with your knee or backside and it's goodnight nurse!

NT; there's different types of RCDs. 10mA, 30mA, and incorporated into power cubes, power points, switchboards and even some appliances. Most incorporate Circuit Breakers (ELCBs) to protect the supply voltage against shorts. However, as far as I'm aware they all act in the same manner: monitoring the active and neutral conductors for imbalance. Whether the "leakage" of current is to ground by an alternative route, or to earth via the conductor is immaterial as far as the RCD monitoring circuit is concerned. It trips in 10-20mSecs. anyway. Which is why they can't be used in MIMS type elements in stoves and h.w. cylinders, but are effective with double insulated elements in kettles & frypans etc.

The Neutral Conductor in any electrical installation is required to be hardwired to the earth conductor and the grounding earth spike/s etc. at the switchboard.

You're kinda there Ratbag ...

An RCD (Residual Current Device) is the same beasty as an ELCB (Earth Leakage Circuit Breaker). An RCD/ELCB will trip when the is a current imbalance between the active and neutral conductors. The ONLY way this can happen is if current "leaks" to earth (or possibly [but unlikely] another conductor NOT associated with the protected active and neutral conductors).

Again, if your body creates a circuit between the active and neutral conductor of an RCD protected circuit (and there is no leakage of current through your body to earth) then the RCD will NOT trip and you will most likely be dead.