Hmm!!

How well do the jaws on your clamp close  when hanging off a cable  like that ?

- I suspect that both 1/4A and 7mA are inaccurate and are more of a representation of neither the live nor neutral currents being centrally positioned (nor equally off centre) in the core, and the cancellation of the magnetic fields getting a few percent out of kilter - perhaps more of the flux from the neutral escaping through the gap in the jaws, or is the steel  getting magnetically non uniform and needs de-gaussing.

How much current is the heater taking - i.e, what % imperfection in the cancellation are we talking about ?

Mike.

Hmm!!

How well do the jaws on your clamp close  when hanging off a cable  like that ?

- I suspect that both 1/4A and 7mA are inaccurate and are more of a representation of neither the live nor neutral currents being centrally positioned (nor equally off centre) in the core, and the cancellation of the magnetic fields getting a few percent out of kilter - perhaps more of the flux from the neutral escaping through the gap in the jaws, or is the steel  getting magnetically non uniform and needs de-gaussing.

How much current is the heater taking - i.e, what % imperfection in the cancellation are we talking about ?

Mike.