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  1. #11

    Default Truck grounding

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    I also agree with the older lineman. Many utilities operating standards suggest using system neutral connections, anchor rods, pole grounds and or driven rods. The key is all crew members stay clear of the truck and outriggers while a live operation is being carried out. I might add the higher the voltage the more gradient step and touch potential is involved. Hot trucks are not always going to cause line protection to react! Pole setting or movements better be planned and respected with live line tools, clean ropes or gloves etc. Pole guards and line guards are your buddies. Grounding and truck design for ball grounds chassis continuity etc. Only protect the trucks not people! If I had a buck for every ripped off grounding clamp or twisted temporary ground left behind I could eat ice cream for the rest of my retirement.
    Follow the local rules but know when it comes to grounding the extension of the grounding zone brings more hazards into play not less.

  2. #12
    Join Date
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    Derrick trucks should always be grounded whether the line is live or grounded (should be the only options) and to the system neutral if available. The reason for grounding RBDs during dead operations is to bond the boom in case of accidental energization to keep it at the same potential as the worker in the air. When working live it is to help clear the line, but the reality is if you touch the truck at the same time as it is accidentally energized you will be badly hurt if not killed.

  3. Default

    Quote Originally Posted by copperlineman View Post
    I'm over 50 years in the business and most of my work was with an Investor owned. The system neutral was our preferred ground and used whenever we could. Steel structures, down-grounds, anchor rods, etc. were next, and that T Rod thing your talking about was a distant last and was hardly ever used with a digger derrick, because it was not connected to the system and it would most likely NOT trip a circuit out. A breaker would probably see it as more AC units/load coming on. Even worse, the T rod could set up a ground gradient as it sought out a path to the station. When connected to the system neutral, the system will see a large increase in current very quickly and the protection device will open quickly. That's why are ground/neutral connections are clean and tight, and the grounding jumpers are large enough in size to handle to current they have to carry. A T rod won't come close to doing that.
    We ground trucks for a few reasons, the most important is a fast trip out of the circuit. This is not an I&I issue as I've read here. I&I is for working equipment energized (isolate & insulate). We are grounding a piece of equipment that we're using NEAR energized stuff so it does not stay energized in case of contact.
    When the boom of a derrick truck is in the air and close to the primary zone (10 feet), NO ONE should approach that truck. The operator stays on the truck until the load is secured. If contact is made, the truck will be energized until the grounding method works and the circuit protection opens (the breaker or fuse). If anyone is contacting the truck when contact is made, that person is in great danger whether the truck is grounded or not. We want the circuit to open as fast as we can, so we ground it to the system neutral to achieve that. We also keep everyone away from the truck and the operator on the truck until the fuse or breaker opens and the danger is past.
    This is exactly what every person who is grounding their digger needs to understand. The purpose of that ground is to trip the circuit, and you need a good, preferably direct path to that system neutral to achieve that quick trip.

  4. Default

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    Quote Originally Posted by rob8210 View Post
    The utility I am doing work for right now requires the rbd to be bonded to the system neutral. Other utilities I have done work for have varied practices. We always ground our truck some way or another , to the neutral , or a pole ground, maybe a temporary ground rod, some places even allow you to ground to an anchor rod. When 2 or more trucks are close together we bond them together. Bucket trucks are another matter depending on if the lower boom has a fibreglass insert and how high the primary voltage is.
    The utility you are currently working for requires the RBD (Residual Bonding Device) to be bonded to the system neutral, which means that the RBD is connected to the neutral point of the electrical system. Other utilities may have different practices, such as grounding the truck to the neutral, a pole ground, a temporary ground rod, or even an anchor rod. When multiple trucks are working in close proximity, they should be bonded together to ensure safety. Bucket trucks may require different procedures depending on the materials used in the lower boom and the primary voltage of the electrical system.

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