Single Static Watthour Meter

This series of meter uses a special CPU to measure electricity. It is 
able to function normally even if the phase and neutral connections 
are interchanged. It will record any alterations in the incoming and 
out-going connections of the meter, i.e. reversed current connections. 
If incorrectly connected, supply will be cut off, that is, earth to 
neutral or vice versa. The load will only be reconnected following 
correct connection, neutral to neutral. Displays residual energy and 
has an overload monitor.