WATER LINE BONDING

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TODD B.

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Can the water line bond be taken to each water line entry when the main water line is outdoors, underground and metallic; and the individual water line taps are metallic coming into each individual tenant space. This is one building, with one service (main service disconnect outside--meter pack) panelboards in each tenant space.
 
TODD B. said:
Can the water line bond be taken to each water line entry when the main water line is outdoors, underground and metallic; and the individual water line taps are metallic coming into each individual tenant space. This is one building, with one service (main service disconnect outside--meter pack) panelboards in each tenant space.
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For complying with grounding electrode and bonding requirements, bonding to one entry is sufficient, IMO.
 
So what do you do when there is multiple water services to a building and each is islolated by Dielectric unions. That would leave some units un-bonded.
 
Sierrasparky said:
So what do you do when there is multiple water services to a building and each is islolated by Dielectric unions. That would leave some units un-bonded.
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Different conditions require different solutions. You obviously would have to bond each isolated system...

OP did not mention location of meters either.
 
If the lines are metalically connected then connect the GEC to the water line within 5' of where it enters the building-- one time back to the main Disconnect.
 
jumper said:
Hmmmm...NEC code or local amendment? Never required to do it myself.
Not saying it is a bad idea, but required by code?
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When we have a complete system in copper pipe,we bond cold to hot at the

water heater due to dielectric unions at water heater. Two waterline clamps &

a short piece of #6 or #4 bare, whatever is handy.
 
TODD B. said:
Can the water line bond be taken to each water line entry when the main water line is outdoors, underground and metallic; and the individual water line taps are metallic coming into each individual tenant space. This is one building, with one service (main service disconnect outside--meter pack) panelboards in each tenant space.
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The metal water pipe that is underground will need to be used as an electrode as outlined in 250.52 and connected to the service disconnect located outside using a conductor from Table 250.66.
The metal water pipe that enters each unit will need to be bonded according to 250.104(A)(2) using a conductor from Table 250.122
 
John120/240 said:
When we have a complete system in copper pipe,we bond cold to hot at the water heater due to dielectric unions at water heater. Two waterline clamps & a short piece of #6 or #4 bare, whatever is handy.
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I've seen that required in some areas, not around here. The mixing valves make the system one. The practice contradicts a panel statement made in the creation of the 2008 NEC:

2007 Proposal 5-236 said:
Panel Statement: The requirements of 250.104(A) apply to complete metallic water piping systems. Where there is no complete metallic water piping system, then the requirements of 250.104(B) would apply for those portions of isolated metal water piping system likely to become energized.
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What is likely to energize the hot water pipes, even if they were electrically isolated (no mixing valves present in the system)?
 
Where is the nonmetallic piping?

(2) Buildings of Multiple Occupancy. In buildings of multiple occupancy where the metal water piping system(s) installed in or attached to a building or structure for the individual occupancies is metallically isolated from all other occupancies by use of nonmetallic water piping, the metal water piping system(s) for each occupancy shall be permitted to be bonded to the equipment grounding terminal of the panelboard or switchboard enclosure (other than service equipment) supplying that occupancy. The bonding jumper shall be sized in accordance with Table 250.122, based on the rating of the overcurrent protective device for the circuit supplying the occupancy.
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He is not required to make use of this alternate provision - he has already bonded the metal water piping with the single GEC. There is no nonmetallic water piping, so technically this permission (which is not written as a requirement) does not apply.

A simple bonding jumper around the meters is all he needs, a handful of water pipe clamps and a foot of copper apiece.
 
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