These devices are basically MOVs that isolate the primary and secondary neutrals under normal conditions, but flash closed when the potential difference exceeds the MOV threshold. They have been available for about 30yrs now but their use creates a hazardous condition for utility service crews due to the introduction of potential difference between neutrals. The secondary neutral must be absolutely solidly grounded to minimize unbalanced loads causing voltage swings on the secondary neutral.

I find it odd that there are no diagrams or photos with this stray-voltage "stopper". I'd like to hear from some dairy farmers that they tried this and if it really works.

good article need information like this, last year first time recorded where by a young boy was kill by 7 volts identified as stay voltage. . like atricle stated we have not address any issue of less then 10 volt before. Now a dealth of only 7 volts be interested what the NEC going to do about it in 2011 keep up the good work Mike.

Very interesting. Is it UL approved? They also need to proof read their brochure.

I have not had the opportunity to use the Ronk Blocker, however, for several years now my company has recommended the Ronk Add-A-Phase product and I have always been impressed with the quality and the level of expertise they offer in support of their products.

When will the electrical industry realize that voltage does not kill? It is current that harms cows and humans. Mike you would do the electrical industry a GREAT favor to get on the band wagon and you can start by showing a picture of a Van de Graaff generator at 400,000 volts and a young gril holding onto the 400,000 volts with her hair standing up.

I have a copy of such a picture from the internet but do not have the address.

To just give voltage as the level of harm without including any of the other required parameters is STUPID misleading. The bases for this statement is algebra where to solve any equation you must give values for one less than the number of parameters. Ohms Law had three unknowns therefore you must give values for two of the unknowns in order to solve the problem - That of finding the current.

However, with electrocution there is a fourth value TIME.

I have not looked at the instructions of the installation of the Ronk recently but I find that the utilites still install the primary neutral connection to earth on one side of the pole while the seconadry neutral to ground connection is installed on the opposite side negating the effectiveness of the blocker.

I only read the PDF file ... It seems to me that for this product to work, there would have to be separation of neutral and ground at the service entrance. How could Code possibly allow this?

I also found it odd that since the information is distributed my Mike Holt, there is at least an implied endorsement.

Probably wrong on both counts ...

I only read the PDF file ... It seems to me that for this product to work, there would have to be separation of neutral and ground at the service entrance. How could Code possibly allow this?

I also found it odd that since the information is distributed my Mike Holt, there is at least an implied endorsement.

Probably wrong on both counts ...