BAP - 3 Phase Supply Monitoring Relay / Phase Failure Relay

BAP - 3 Phase Supply Monitoring Relay / Phase Failure Relay

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Aplication:     Supply Monitoring relay, panel mounted, to monitor an essential 3 phase supply for under-voltage, phase imbalance, phase rotation and time delay.


For the accurate detection of Symmetrical Under Voltage and Asymmetrical Phase Imbalance and Phase Rotation on a 3 phase AC supply coupled with the user friendly Calibrated controls, for the setting of both under voltage and phase imbalance trip levels, the BA range is listed amongst the most popular Supply Monitoring Relays that Midland Jay manufacture.

Active Filters are included within the measuring circuits aimed at reducing the risk of errors or nuisance tripping caused by harmonics and True, visible, indication of the output status of the device is achieved by means of a dual colour LED. Within the range there is a choice of having a Trip Delay time or a True Delay time.


A.     For a enclosed version see the BAE range

B.     For a supply monitoring relay with under-voltage and over-voltage see the BBP range


For the product to suit your application please see the selection chart below or contact sales:
Use Filter menus to browse products - 1 Filter(s) Set
ProdRefSupply VoltageU/V Trip LevelImbalance Trip LevelPhase RotationTrip Delay TimeopenTimer TypePower on Delay TimeRelay ContactsEnclosure Typeenclosure type
BAP1201add to basket110Vac75%15%Yes0.5 secsFixed0.3 secs1 pole C/O1
BAP1401add to basket110Vac75%5-15%Yes0.5 secsFixed0.3 secs1 pole C/O1
BAP1501add to basket110Vac75-95%15%Yes0.5 secsFixed0.3 secs1 pole C/O1
BAP1601add to basket110Vac75%15%Yes0.5 secsFixed0.3 secs2 pole C/O1
BAP1701add to basket110Vac75%5-15%Yes0.5 secsFixed0.3 secs2 pole C/O1
BAP1801add to basket110Vac75-95%15%Yes0.5 secsFixed0.3 secs2 pole C/O1
BAP1901add to basket110Vac75-95%5-15%Yes0.5 secsFixed0.3 secs2 pole C/O1
BAP2701add to basket110Vac50-95%5-15%Yes0.5-30 secsTrue1.3 secs2 pole C/O2
BAP2901add to basket110Vac50-95%5-15%Yes0.5 secsFixed2-30 secs2 pole C/O2

Trip Delay Timer
Where fitted the ‘Trip Delay Timer’ will inhibit the output contacts from releasing immediately a fault is detected.
The trip delay time is adjustable up to either 10 or 30 seconds depending on the model and will be either a ‘Standard’ delay or a ‘True’ delay type.
The 'Standard' delay type will require around 50% nominal supply voltage to be maintained for its operation, in the case of a total loss of power the unit
will trip with a minimal delay of approximately 0.5 seconds. This type of timer will allow the unit to ride through a short term voltage dip but not a total
power loss.
The 'True' delay timer is not dependent on the supply voltage for its operation. The timing function will be available in the case of either a partial or total
supply failure. This type of timer will allow the unit to ride through either a short term voltage dip or a total loss of power lasting up to 30 seconds.
Power On Delay Timer
Where fitted, the ‘Power On Delay Timer’ will delay the output contacts from energising immediately the supply voltage is applied to the unit for a period
of up to 30 seconds.
The supply voltage will have to satisfy the conditions set by the supply monitoring relay for a healthy supply continuously for the ‘Power On Delay’ timing
period before the output contacts will energise.
If the unit detects a fault and releases the output contacts the supply voltage will once again have to satisfy the requirements of a healthy supply continuously
for the ‘Power On Delay’ timing period before the output contacts will re-energise.