DETAILED DESCRIPTION

PMA50

The PMA50 is a Lovato Electric electronic devise which includes 4 motor protections:
phase sequence, phase loss, over-current and too low motor load by controlling the cosϕ value.
The relay finds its ideal application in the protection of pumps since it conducts control functions to exclude dry pump running and to stop it. It can be also used to detect the breakage of transmission mechanisms, such as belts, joints, and to protect against the blockage of a transmission system.
It has an automatic reset time for under-load tripping. This function provides for the pump restarting once the well level is restored.

CHARACTERISTICS
– Under-load control (dry running) by cosϕ measurement
– TRMS maximum current control
– Power supply voltage separated from control voltage
– Sequence and phase failure control
– Connection either directly or by external CT
– Consent input for running/resetting
– Current input: 16A
– Choice of 2 current scales: 5A or 16A
– cosϕ MIN threshold adjustment:  0.1...0.99
– MAX current threshold adjustment: 10...100%
– Inhibition time: 1...60s
– Tripping delay: 0.1...10s
– Automatic reset delay: OFF...100min
– Fixed hysteresis: 0.03cosϕ and 3% for overcurrent