adding surge protectors in LB connector
- Thread starter mikefamig
- Start date
Two more points that I need cleared up about grounding the Ditek surge suppressor.
First is it best to isolate the ditek ground wire from it's metal enclosure so that the enclosure doesn't become energized in a lightning strike?
And the second detail is about the ground lead itself. In my garage the enclosure for the surge is next to the electric sub-panel that powers the garage. The sub panel is grounded to a stake in the earth outside via an awg6 wire.
Should I
1 - just tap the ditek ground into the awg6 wire that runs from the sub panel to the stake in the earth outside
2- run a second awg6 wire from the ditek all the way out to the stake in the earth outside
or
3 should run a second awg6 wire from the ditek to it's own newly installed stake in the earth?
It seems best for it ti have it's own wire and stake so that the sub panel does not get energized in a lightning strike but is it necessary or overkill.
Mike.
First is it best to isolate the ditek ground wire from it's metal enclosure so that the enclosure doesn't become energized in a lightning strike?
And the second detail is about the ground lead itself. In my garage the enclosure for the surge is next to the electric sub-panel that powers the garage. The sub panel is grounded to a stake in the earth outside via an awg6 wire.
Should I
1 - just tap the ditek ground into the awg6 wire that runs from the sub panel to the stake in the earth outside
2- run a second awg6 wire from the ditek all the way out to the stake in the earth outside
or
3 should run a second awg6 wire from the ditek to it's own newly installed stake in the earth?
It seems best for it ti have it's own wire and stake so that the sub panel does not get energized in a lightning strike but is it necessary or overkill.
Mike.
First is it best to isolate the ditek ground wire from it's metal enclosure so that the enclosure doesn't become energized in a lightning strike?
Think about voltages differences. Do you want your circuits to be at different voltages where the tendency is to discharge via your electronics through to the metal cabinet they are mounted on?
Think about the humans. Do you want somebody leaning against the cabinet to have a voltage on the cabinet that isn't on their feet or other hand.
Connect all together inside the cabinet to the cabinet (usually a stud passthrough the metal cabinet) and then connect cabinet (other end of stud) to garage panel ground. Reduce any differences in voltage on items that are in close proximity, generally.
Think about voltages differences. Do you want your circuits to be at different voltages where the tendency is to discharge via your electronics through to the metal cabinet they are mounted on?
Think about the humans. Do you want somebody leaning against the cabinet to have a voltage on the cabinet that isn't on their feet or other hand.
Connect all together inside the cabinet to the cabinet (usually a stud passthrough the metal cabinet) and then connect cabinet (other end of stud) to garage panel ground. Reduce any differences in voltage on items that are in close proximity, generally.
LarrylLix said:
I understand and agree with this in the AC load center and the sub panel but I am talking about a metal enclosure with only the Ditek surge protector in it. The conductors are cat5e (12vdc rs485 and 5vdc ip).
Is bonding the cabinet the correct thing in this case? The cat5e doesn't carry enough current to be dangerous but the ground lead just might in a lightning strike. If I tie the Ditek ground to the cabinet then the cabinet becomes charged in a strike which I would think is a potential hazard to anyone touching it..
Mike.
EDIT - Think of this. If the buried cat5e gets a surge and carries it into the building and into the Ditek isn't it safer if the ground lead carries that surge out to a ground stake without conducting it to the cabinet?
RAL said:
I'M convinced and I've committed to installing the surge at the entry point to each building. I had enough extra cable in the conduit on the garage end to go up the the house and pull the entire bundle back a few feet so that the splice that used to be in the Lbox on the house exterior is now in the basement where I can install an enclosure.
Mike.
Bonding to a cabinet is only for safety purposes 99% of the time, with the secondary purpose to drain transients to ground, usually the equipment is electrically isolated from any bond or ground of the enclosure itself. The purpose of bonding the can is to bleed any HV faults that may exist to ground, not surges.
While it's not a bad idea, it's not necessary in this case.
If you had HV in the can, then I could see the need or where it'd be desirable, but LV only, no.
While it's not a bad idea, it's not necessary in this case.
If you had HV in the can, then I could see the need or where it'd be desirable, but LV only, no.
Neurorad said:
This Ditek surge protector ground has nothing to do with and is completely isolated from the house's AC electric service. It is also completely isolated from and has nothing to do with the Elk's power system. It is simply a device that the rs-485 conductors pass through similar to a wire terminal strip with the added capability of diverting large power surges safely to an earth ground. The ground is not connected to the house's ground rods or the Elk's power system.
The AC power to the house has two ground rods about 8' apart from each other that are connected to each other and also connected to the ground bar in the house's load center. This is the foundation of the house's entire bonding grid. The power sub-panel in the detached garage is also connected to these in addition to a pair of stakes in the earth just outside the garage. This is all completely unrelated to the Elk. The M1 install manual specifically instructs to NOT connect the Elk to the electrical ground system or any earth ground at all.
No the metal cabinet is not connected to anything else and could just as well be plastic. I am just curious if it might not be safer to isolate the ditek ground from the cabinet so that the cabinet never carries any current.
Mike.
I decided that I've been wasting a lot of time trying to take a short cut so I went down to home depot and came home with a couple of 8' ground rods and drove them into the ground today each within about 6' of the surge devices.
Every time I think that the security system is fully installed the job gets bigger. I severely underestimated the hours involved in this installation when I was planning it a year or so ago.
Mike.
Every time I think that the security system is fully installed the job gets bigger. I severely underestimated the hours involved in this installation when I was planning it a year or so ago.
Mike.
That's what I get after posting while having a cold one....
You're a better man than me Mike. The supplementary rods weren't really necessary in this case and you could've bonded to the existing ones installed for the service.
Bonding the enclosure won't hurt, but it's not necessary either. The cabinet doesn't have the real possibility to carry current unless you have a LV ground fault.
And yes, the M1 is supposed to be isolated (no EG necessary) as you already posted. Usually most alarm panels perform best with no EG in the case of a surge (but then again, the surge typically feeds in via telephone and out via the transformer/neutral).
You're a better man than me Mike. The supplementary rods weren't really necessary in this case and you could've bonded to the existing ones installed for the service.
Bonding the enclosure won't hurt, but it's not necessary either. The cabinet doesn't have the real possibility to carry current unless you have a LV ground fault.
And yes, the M1 is supposed to be isolated (no EG necessary) as you already posted. Usually most alarm panels perform best with no EG in the case of a surge (but then again, the surge typically feeds in via telephone and out via the transformer/neutral).
DELInstallations said:
The stakes went into the ground relatively easily after all of the rain that we've been having, it took less than an hour to do both. One of the reason't that I did it was because it is a pretty long distance that I would have to run a wire to get to an existing ground on the house end and the new stake will be short and easy. Every foot that you add to the ground lead on the Ditek takes away from it's efficiency. Everything that I've read stressed keeping the ground run as short as possible. It gives me some peace of mind.
Mike.
Here is something interesting that I found while researching surge protection. It's a Ditek option for situations where no earth ground is available or practical to reach with a wire.
http://www.ditekcorp.com/product-details.asp?ProdKey=54
http://www.ditekcorp.com/product-details.asp?ProdKey=54
