Blind Measuring Module

BMM (Blind Measuring Module) is multi functional unit which supports only 3P4W installation. BMM take 3 Voltage inputs & 3 Amps inputs for measurement. BMM measures phase wise Voltage, Amps, PF, Power as well as System Power, Energy,Frequency. For demand calculation BMM has Fixed 30 Minute window, based on Real Time Clock for KW as well as KVA.

BMM provides one RS485 port with Modbus-RTU protocol to communicate with external world. As BMM receive any data over RS485 then “RxD” led will glow and if BMM is responding over RS485 then “TxD” led will glow. As unit power up, “POWER” led glows.

BMM provides pulse on led (1000 Pulse/KWh) as well as on isolated opto coupler.


Type Name Statistics
Input Supply Three Phases and Neutral of a 3P4W system
Voltage Direct Voltage Input : Up to 300V L-N
PT Ratio : 1
Burden : 1 VA
Current Secondary Current Input: - -
CT Ratio : 1
Range of Reading : up to 70 Amps
Burden : < 1.0VA
Overload : 75A RMS Continuous
PowerSupply Auxiliary Supply: 90 - 270 VAC (P-N), 50-60 Hz. (Power Up from 3 Phase Voltage Input)
MEASUREMENT True RMSBasicParameters Voltage(Volts L-N & L-L) VL-N Accuracy : 0.5% of Reading
VL-L Accuracy : 1.0% of Reading
Current(Amps IR, IY, IB) Accuracy : 1% of Reading
Line Frequency 46.5 to 63.5 Hz, Accuracy : 0.3% of Reading
Power Active Power (P) Accuracy : 1% of Reading(For IPFI>0.5)
Reactive Power (Q) Accuracy : 1.5% of Reading(Between 0.5 Lag to 0.8 Lead)
Apparent Power (S) Accuracy : 1% of Reading
Power Factor For Individual phases and System.
Accuracy : 1.0% of Reading (IPFI≥0.5)
Range of Reading : 0.05 to 1.00 Lag/Lead
Energy Total Active Energy (KWh) Range of Reading : 0 to 9999999.9 KWh
Accuracy : Class 1 as per IS13779
Total Apparent Energy (KVAh) Range of Reading : 0 to 9999999.9 KVAh
Accuracy : Class 1
Total Apparent Energy (KVARh) Range of Reading : 0 to 9999999.9 KVARh
Accuracy : Class 1
Demand Active Power (KW) Demand – 30 Minute Fixed Window
Apparent Power (KVA) Demand - 30 Minute Fixed Window