Dan Mulligan
Member
But does it need to be bonded based on the service size or the largest circuit most likely to energize the piping system 250.104 B 1 and in this case the only circuit in the vicinity would be 20 amp.
Sprinkler Main Bonding
- Thread starter Dan Mulligan
- Start date
It's metal water piping so I would think 250.104(A),,,, service size.
Dan Mulligan
Member
If it were gas piping would you run a 3/0 to it? Typical the gas pipe is bonded thru the appliance. Isn't the sprinkler pipe the same as gas pipe in regards to bonding?
- Location
- Illinois
- Occupation
- retired electrician
Gas piping has its own rule in 250/104(B), and its bonding is based on the rating of the circuit that is likely to be energized.
Not sure why the rules for water piping and other piping are different as the hazards are identical.
But does it need to be bonded based on the service size or the largest circuit most likely to energize the piping system 250.104 B 1 and in this case the only circuit in the vicinity would be 20 amp.
Doesn't that depend on were the Fire Pump is located? Generally the motor controller for the Fire Pump is service equipment. How close is that? There may also be a Fire Department Connection Siamese or manifold inlet which is usually metallic piping. If the Utility's Water Main in the street is metallic of otherwise conductive, such as reinforced concrete piping, it will provide a conductive path between the 2 water service lateral lines. The concern may be that many fire sprinkler supply laterals are being assembled with Victaulic Couplings. Those function as an insulating coupling. When the subway system was built in Washington DC the electricians had to bond around every Victaulic coupling. That was before I came there so I don't know why.
Tom Horne
Doesn't that depend on were the Fire Pump is located? Generally the motor controller for the Fire Pump is service equipment. How close is that? There may also be a Fire Department Connection Siamese or manifold inlet which is usually metallic piping. If the Utility's Water Main in the street is metallic of otherwise conductive, such as reinforced concrete piping, it will provide a conductive path between the 2 water service lateral lines. The concern may be that many fire sprinkler supply laterals are being assembled with Victaulic Couplings. Those function as an insulating coupling. When the subway system was built in Washington DC the electricians had to bond around every Victaulic coupling. That was before I came there so I don't know why.
Tom Horne
Strathead
Senior Member
- Location
- Ocala, Florida, USA
- Occupation
- Electrician/Estimator/Project Manager/Superintendent
I would posit that a sprinkler system is not "the metal water piping system" any more than a sewer piping system would be a metal water piping system. Both have water in them, but their purpose is different. As such bonding would be to the size likely to energize it.
Given the current required to turn a fire pump at the design volume of the fire sprinkler system that bonding conductor may still end up being quite large.
Tom Horne
GregC1978
New User
- Location
- Orlando, FL
- Occupation
- Project Manager
It appears your building official is basing his suggestion on table 250.122 used for sizing equipment grounding conductors, which is not the correct application of the code. System bonding jumpers are now determined by table 250.102(C)(1), which is based on circular mills instead of overcurrent protection. We have always bonded all metallic systems including fire sprinkler piping and is typically called out by the EOR on the electrical plans.