Hi Marcspages. Insulated bars & testing tap-offs with removable covers are a great idea but unfortunately would triple the cost of a CT chamber, and Electrical Engineering Consultants always have one eye on the money and don't consider making safe provisions for power analysis testing without a shut-down later on.
I guess the Metering CT chamber is an obvious choice for live power analysis meaurement when a shut-down is inconvenient
I can imagine how putting clamps & croc clips on bare bars could be very nerve-racking. I would wear a welding helmet and a thick pair of rubber gloves.
The OSH rules in NZ forbid persons working on or in the vicinity of live parts. Unless there is an approved procedure in place to minimise risk of injury etc.
So unless their is a CT chamber with properly shielded testing points, the main switch should be off while you connect your test leads. This may mean that you have to get up in the middle of the night to do the shut-down, but its still preferable to attaching leads to bare live bars. Fault currents are very high at CT busbars and one tiny mistake can cause a big bang.
Also you can charge more for "after-hours work".
