Monitoring a 400A Supply with a Variable Tariff
Challenge
Our client was looking to monitor a 400A 3-phase circuit that was split off from their primary meter and supplying an industrial unit. They were on a variable tariff, allowing them to benefit from cheaper rates of electricity at off-peak hours, but their existing contract was due to expire in 6 months time. They were unsure what times their new tariff would offer so wanted the flexibility of being able to re-program their meter to match the new tariff.
Solution
While most meters require the manufacturer's software to program tariff times onto them, a selection of DIN Rail & Panel Mount meters allow tariff switching using a digital time clock that can be supplied separately.
S P Wales mounted Carlo Gavazzi's EM330 onto the front of a steel enclosure with a 24 hour digital time clock fitted inside. We included links to easily wire in the CT's and fuses for the voltage references along with a metre of cable allowing them to tap off from the existing supply.
The resulting pre-wired enclosure was fitted next to the distribution board with the split-core CT's easily clipping round the existing supply. The time clock, fitted within the lockable enclosure, allows the tariff times to be adjusted as required, and with the meter being mounted on the front of the enclosure, the consumer has full visibility of consumption, with no risk of tampering.