Rayleigh instruments ri 7x series single phase mid certified meters rayleigh instruments ri 76 100 p the rayleigh instruments ri 76 100 p is a mid approved and certified b amp d single phase network kilowatt hour active energy meter it is housed in a 76mm wide 4 module din rail mounting enclosure it can be directly connected up to 100 amps and has pulse output 1000 impulses kwh as standardthe use of mid certified electricity meters has been made mandatory on private electrical n