100 ma is quite a bit above shock hazard, but as a parallel bath for neutral current from the service to the transformer I don't think it is uncommon.Does low mean more amps or less amps? 100 ma is close enough to shock hazard; wet environment here. And I know its been posted on these forums quite a few times how dangerous marina wiring can be.
Where does its say monitoring is required??
How would you do it?The main overcurrent protective device that feeds the marina shall have ground fault protection not exceeding 100ma
Well I did just contribute something helpful. I showed that what you said is not true, monitoring is not required by code as you stated it was. I don't know how I would do it because unless the customer specifically asked for it I wouldn't do it. I have done quite a few marinas and never monitored the ground fault and never had an issues. You are giving a new meaning to the old saying" making a mountain out of a mole hill"hardworkingstiff said:How would you do it? If you would put a ground fault main in, the main breaker "monitors" current for ground faults and trips when called for. No warning, no indication of where the problem came from, nothing but slam off. The product I am looking at will monitor the current and send a warning as fault current rises before it reaches trip level (of course unless it's a quick low resistance fault). Depending on how you route the service grounding conductor you can monitor the current going to ground or not. Anyway you seem to be arguing that the word "monitor" is not in the code, and I will concede that point with the argument that you cannot comply with the code unless you install something that will monitor ground fault current. So, now that you got me to admit that I did not quote the code verbatim, would you care to contribute something helpful?
http://ecmweb.com/content/how-gfcis-workA GFCI is specifically designed to protect people against electric shock from an electrical system, and it monitors the imbalance of current between the ungrounded (hot) and grounded (neutral) conductor of a given circuit.
I'm assuming the "cups of rice" were used as a metric on the intensity of the shock. I can just imagine the lab report:These values were set by tests at Underwriters Laboratories during which volunteers holding cups of rice were subjected to shocks of known amperage and voltage. Initially, the GFCI was developed using pigs and hogs in swimming pools, because their skin is like that of humans.
There is what's called an Under Voltage Trip as opposed to a Shunt Trip. they trip the mechanism in the breaker when you LOSE power to it's coil. But be forewarned, you have to think through wanting to have to reset the breaker EVERY time you lose power for ANY reason.Thank you.
The customers do not want to lose there whole service due to the actions of one boat. So, it looks like the Bender unit with shunt trip breakers for the feeders to the dock pedestals.
The problem I have is this thing fails in the on position as far as power going to the docks. In other words, if the power to the output relays of the Bender unit drops out (for whatever reason) then the Bender unit closing a relay won't send power to the shunt trip breaker. If the Bender unit loses power there is no protection, and no interruption of power.
Do they make a shunt trip breaker that takes continuous power to allow the breaker to close and the loss of power will cause the breaker to open?
I was trying to see if I could just use GFP branches, but it seems that most of them are designed for 3-phase (no neutral) circuits, or don't go to the ampacities I need (100 to 200-amp single-phase).
LOL, gotta love Wikipedia and open editing. I think some people make a game of trying to get things into articles as jokes. I revisited that page and the "cups of rice" thing is gone. But now it says this!Funny side note: I read this a few months back when having a similar discussion on GF in ETU main breakers. It was apparently discussing GFCIs, but was misapplied to the Wiki article on Residual Current Detectors, the European version of our GFCIs. I just thought it was worth a chuckle:
I'm assuming the "cups of rice" were used as a metric on the intensity of the shock. I can just imagine the lab report:
"Subject A was subjected to 3ma for 25 seconds, spilling 14 grams of rice. Subject B was subjected to 8ma for 25 seconds and spilled 220 grams of rice. Clearly 8ma is too much..."
:laughing:A residual-current device (RCD), or residual-current circuit breaker (RCCB) or residual twin-direct current couplet (R2D2), is an electrical wiring device that disconnects a circuit whenever it detects that the electric current is not balanced between the energized conductor and the return neutral conductor.
If you watch Tosh.0 he has challenged people to do just that.I think some people make a game of trying to get things into articles as jokes.