Q: Do I need to shut down my equipment to do this inspection?
A: The plant needs to be operational during the inspection. Fully loaded is the optimum for an infrared scan. A poor electrical connection generates heat that can cause power loss at the connection. The higher the current flow, the more power will be dissipated.
Q: Is a hot spot bad?
A: A hot terminal connection affects your system in various ways: ·It is a power loss: You are paying extra in your electrical bill for all hot connections. The electrical meter does not care where the power is going, whether to turn a motor or heat the air. Therefore a hot connection reduces plant efficiency.
·Failure: Most damage occurs when the electrical connection actually fails. The arc that is caused when the connections separate will melt most metals. A connection that would have cost $200 in parts and labor to repair before failure could cost the owner in excess of $500,000 if it goes to failure.
·Fires: caused by the failure of the connection can, and have, destroyed an entire complex.
Q: Aren't all electrical connections hot?
A: Any electrical system normally operates at a temperature slightly above ambient; in some cases well above ambient. Problem connections are in excess of these temperatures.
Q: Why is it hot?
A: All electrical connections and even straight runs of cable offer resistance to current flow. This resistance is a system power loss that is dissipated as heat. This is normal. The electrical connection that is as little as .5 degrees celsius hotter than the others can be detected.
Q: Say a panel has been in place for 25 years. I don't think it’s going to fail. Shouldn’t we just leave it alone?
A: Failure due to an overheating condition cannot be accurately predicted. When an electrical connection starts to form high resistance and generate heat, there is no method to determine when it will fail. A connection could be elevated in temperature for two or three years and fail in the fourth year. On the other hand, the connection may never fail.
Q: Our equipment is new. There is no reason to check it, is there?
A: Unfortunately, age has no relationship to hot connections. Poor initial installation has been the cause of many failures.