We are being asked to preform "load calculations more and more on existing properties.
in 95% of the cases the supply is 3 phase 220/380 v, but all loads are single phase.
Grounding is most of the time either bad or non existent.
The neutral is almost never bonded to the ground.
We do install 2 meter 5/8 ground rods and merger the connection.
WE do bond the neutral to the ground at the entrance panel.
In many cases there is no ground bar in the panel (panel/distribution) box locally built with bus bars, with the load side distributed to a 3 phase sub-panel.
When we take on or inspect a project we attempt to balance the loads in the sub-panels.
I am looking for a way to make a realistic load calculation for the customer.
These load calculations are usually used to determine if the local/onsite transformer and underground wiring are adequate to add additional loads or if a new larger transformer is required.
I realize this expiation is very basic, but things here are very basic and usually don't follow "Accepted Engineering Practices"
We try and follow NEC and British codes when possible, as you can imagine we must be creative and logical in many cases.
Our primary goal is that whet we do or recommend "IS SAFE" and we will not do anything to compromise safety of either the customer or our technicians.
I am looking for help and advice from you.
I have been associated with forums in the past, we have what we have and no we do not the luxury of "getting a qualified person"
Advice and help is what I need at times. That's what I am looking for. We are not able to follow the codes or rules many times, so we do what we can to "make it safe"
One more question, How do I protect against a HOT neutral
I am an older Engineer and try to keep up with the latest codes, rules, ect. But we do not have either the parts or technology to impliment most of them, not to mention the cost and availability here.
Thanks for your help and understanding.
Farang
in 95% of the cases the supply is 3 phase 220/380 v, but all loads are single phase.
Grounding is most of the time either bad or non existent.
The neutral is almost never bonded to the ground.
We do install 2 meter 5/8 ground rods and merger the connection.
WE do bond the neutral to the ground at the entrance panel.
In many cases there is no ground bar in the panel (panel/distribution) box locally built with bus bars, with the load side distributed to a 3 phase sub-panel.
When we take on or inspect a project we attempt to balance the loads in the sub-panels.
I am looking for a way to make a realistic load calculation for the customer.
These load calculations are usually used to determine if the local/onsite transformer and underground wiring are adequate to add additional loads or if a new larger transformer is required.
I realize this expiation is very basic, but things here are very basic and usually don't follow "Accepted Engineering Practices"
We try and follow NEC and British codes when possible, as you can imagine we must be creative and logical in many cases.
Our primary goal is that whet we do or recommend "IS SAFE" and we will not do anything to compromise safety of either the customer or our technicians.
I am looking for help and advice from you.
I have been associated with forums in the past, we have what we have and no we do not the luxury of "getting a qualified person"
Advice and help is what I need at times. That's what I am looking for. We are not able to follow the codes or rules many times, so we do what we can to "make it safe"
One more question, How do I protect against a HOT neutral
I am an older Engineer and try to keep up with the latest codes, rules, ect. But we do not have either the parts or technology to impliment most of them, not to mention the cost and availability here.
Thanks for your help and understanding.
Farang