chazbolin
Well-Known Member
If you have any question as to how safe is your current main electric service, if it will safely handle increased grow loads then this is the place to drop some photos and get some feedback. The problems that can occur should be considered from the point of incoming electric service on the line side of the electric meter(s) where there is no fusible or main circuit breaker protecting the wires. The cumulative load at these service head wires can easily exceed the maximum current carrying capacity of the wire and when you couple that with the sun beating down on the insulation for years at a time these wires get stiff, oxidation occurs at the connections (this creates higher resistance and voltage drops) and the insulation will begin to shed exposing bare conductors to grounded surfaces.
I was at a property not too long ago that a patient has a small grow going. He's been having dimming lights issues and ballasts running really hot and burning out prematurely. We added up the HID/fans/pumps etc loads and he was drawing with everything running just over 4000 watts. While I'm not a huge fan of HID I couldn't blame any of his problems on the room. The problems were from the main incoming service.
This particular property consists of 3 single family homes and a duplex all on one parcel. The utility feeds the overhead service off of an alley with wires that are large enough to supply 200-300 amps 120/240. All good, from the utility wires sizing for a property this size. But as you will see by the pictures below, this 1940's property is all 'knob and tube' wiring in the walls, that means no ground wire and cloth covered insulation that is 70 years later still providing tenants with their basic electrical needs. And those needs have increased over the years. Now add in even the small grow room and you have an accident just waiting to happen.
This is a tenant to a property owner who is either ignorant, cheap or doesn't care. At some point in the not to distant future this property is going to have an electrical fire. Hopefully it's the type of fire that burns itself out or this old structure(s) will go up like matchsticks. The problem this grower has is that no matter what the cause is he's going to be blamed for causing the fire. And it's not like they can tell the owner to fix the incoming service either. Who ever looks at that unless there's a problem?
If you have an electrical system that is anything similar to these photos then think long and hard about your grow equipment contribution to that systems eminent failure.
Five properties fed off the single overhead service entrance at the rear of the property
The alley where overhead service picks up the utility drop. The vertical weatherhead conduit to the left drops down inside the wall and services three flush mounted 120v meterbases. If you look closely you can see the size of the wire is maybe a no 10 solid for all 3 meters and the insulation is for the most part gone. The horizontal weatherhead runs across the roof and overhead feeds two medium size 1,200 sq ft homes on two more meters at the front of the property.
Two of these three meters feed two apartments off the alley and a laundry room.
The third meter is feeding this small 700 sq ft single family residence. All the loads from the horizontal riser accumulate at the weatherhead for these three units.
At the back units you can see a triplex type of overhead service that runs at an angle to the 700 sq ft residence in the previous picture. Whats noteworthy here is that is you can see the entire service to that small residence is in a conduit within the attic of the duplex and there is no fusible protection of that service while ran in the attic. The loads that are put on this system by your neighbor can easily fuck this duplex up as the conduit itself becomes a heating element.
The three bare wires (maybe a no 12) are what go over to service the two front houses.
Here you can see the three bare overhead wires which are technically still utility wires but customer 'owned and maintained' since they are on the line side of the meters that you can see at the corner of the house.
As you take a close look at the wires coming out of the horizontal conduit and weatherhead that services these two meters they look to be sized nicely for an incoming service capable of delivering somewhere around 80-100 amps @ 120/240V. Of course that is is misleading since you only have to trace back the overhead drop to the duplex and you can see that at best you might pull 30 amps 240 off of the overhead wires. Again since there is no fusing of these overhead wires the cumulative loads at the alley weatherheads and what is referred to as the utility point of service (POS) is going to be the weak link in this system. Not having any fusible protection on the front two meters, one can only hope that a failure in this system will only result in a wire burning through and not going to ground.
Going to ground is normally a good thing in the way of protection but in this case there are no systems grounds like a ground wire, ground rod, cold water bond at any point in the service. When voltage tries to go to ground and that path is not managed by a ground conductor it will lay in wait until such time that another path to ground can be found. That path can be you touching a metal surface of a light or appliance while being barefoot. This can have deadly results. I even had a client that claimed they were getting shocked in the shower. This too can happen as when the water was running it offered a better path to ground then the ground rod connection that had failed (soil resistivity) and the cold water bond was only completed as the water ran since the water meter had not been jumped out with a wire.
I was at a property not too long ago that a patient has a small grow going. He's been having dimming lights issues and ballasts running really hot and burning out prematurely. We added up the HID/fans/pumps etc loads and he was drawing with everything running just over 4000 watts. While I'm not a huge fan of HID I couldn't blame any of his problems on the room. The problems were from the main incoming service.
This particular property consists of 3 single family homes and a duplex all on one parcel. The utility feeds the overhead service off of an alley with wires that are large enough to supply 200-300 amps 120/240. All good, from the utility wires sizing for a property this size. But as you will see by the pictures below, this 1940's property is all 'knob and tube' wiring in the walls, that means no ground wire and cloth covered insulation that is 70 years later still providing tenants with their basic electrical needs. And those needs have increased over the years. Now add in even the small grow room and you have an accident just waiting to happen.
This is a tenant to a property owner who is either ignorant, cheap or doesn't care. At some point in the not to distant future this property is going to have an electrical fire. Hopefully it's the type of fire that burns itself out or this old structure(s) will go up like matchsticks. The problem this grower has is that no matter what the cause is he's going to be blamed for causing the fire. And it's not like they can tell the owner to fix the incoming service either. Who ever looks at that unless there's a problem?
If you have an electrical system that is anything similar to these photos then think long and hard about your grow equipment contribution to that systems eminent failure.
Five properties fed off the single overhead service entrance at the rear of the property
The alley where overhead service picks up the utility drop. The vertical weatherhead conduit to the left drops down inside the wall and services three flush mounted 120v meterbases. If you look closely you can see the size of the wire is maybe a no 10 solid for all 3 meters and the insulation is for the most part gone. The horizontal weatherhead runs across the roof and overhead feeds two medium size 1,200 sq ft homes on two more meters at the front of the property.
Two of these three meters feed two apartments off the alley and a laundry room.
The third meter is feeding this small 700 sq ft single family residence. All the loads from the horizontal riser accumulate at the weatherhead for these three units.
At the back units you can see a triplex type of overhead service that runs at an angle to the 700 sq ft residence in the previous picture. Whats noteworthy here is that is you can see the entire service to that small residence is in a conduit within the attic of the duplex and there is no fusible protection of that service while ran in the attic. The loads that are put on this system by your neighbor can easily fuck this duplex up as the conduit itself becomes a heating element.
The three bare wires (maybe a no 12) are what go over to service the two front houses.
Here you can see the three bare overhead wires which are technically still utility wires but customer 'owned and maintained' since they are on the line side of the meters that you can see at the corner of the house.
As you take a close look at the wires coming out of the horizontal conduit and weatherhead that services these two meters they look to be sized nicely for an incoming service capable of delivering somewhere around 80-100 amps @ 120/240V. Of course that is is misleading since you only have to trace back the overhead drop to the duplex and you can see that at best you might pull 30 amps 240 off of the overhead wires. Again since there is no fusing of these overhead wires the cumulative loads at the alley weatherheads and what is referred to as the utility point of service (POS) is going to be the weak link in this system. Not having any fusible protection on the front two meters, one can only hope that a failure in this system will only result in a wire burning through and not going to ground.
Going to ground is normally a good thing in the way of protection but in this case there are no systems grounds like a ground wire, ground rod, cold water bond at any point in the service. When voltage tries to go to ground and that path is not managed by a ground conductor it will lay in wait until such time that another path to ground can be found. That path can be you touching a metal surface of a light or appliance while being barefoot. This can have deadly results. I even had a client that claimed they were getting shocked in the shower. This too can happen as when the water was running it offered a better path to ground then the ground rod connection that had failed (soil resistivity) and the cold water bond was only completed as the water ran since the water meter had not been jumped out with a wire.