Phase Monitoring Relays, Alternating Relays, and Pump Seal Failure Relays AutomationDirect now offers three types of monitor relays for motor control. The phase monitoring relays provide protection against premature equipment failure caused by undervoltage or overvoltage faults on 3-Phase systems. Phase monitoring relays also protect against single phasing. Alternating relays are used for motor load protection in special applications where optimization of load usage is required by equalizing the run time of two loads. Pump seal failure relays are designed to monitor the shaft seals of submersible pumps for leakage.
Single or dual channel seal failure relays are available for monitoring one or two pumps.
Phase Monitoring Relays
All ProSense 3 phase monitor relays are designed to be compatible with typical Wye or Delta systems. Phase monitoring relays protect against single phasing regardless of any regenerative voltages. These monitor relays are also known as overvoltage relays, undervoltage relays, voltage monitoring relays, or phase loss relays used for phase monitoring and phase loss protection.
- PMRU Series provides protection against phase loss, phase reversal, phase unbalance, undervoltage and overvoltage conditions.
- PMRR Series provides protection against phase reversal.
- PMRRL Series provides protection against electric motor phase loss, phase reversal and undervoltage conditions.
Alternating Relays
The alternating action for motor load control is initiated by a control switch, such as a float switch, manual switch, timing delay, pressure switch, or other isolated contact. Each time the initiating switch is opened, the output relay contacts will change state, thus alternating the two loads.
- AR Series alternating relays have a three-position selector switch that allows the unit to alternate the two loads as normal, or lock the relay to one load or the other.
- ARX Series alternating relays have a three-position selector switch that allows a DPDT cross-wired unit to alternate the two loads as normal, or lock the relay to always operate the same load first each time.
Pump Seal Failure Relays
A resistive-measuring probe provided by the pump manufacturer is installed in the pump seal cavity. If the seal starts to leak, contaminating fluid enters the seal cavity, lowering the resistance between the internal probe and the common connection.
- PSFR series pump seal failure relays are designed to monitor the shaft seals of submersible pumps.
Two pump seal failure relays are available:
- 8-pin SPDT single channel relay
- 8-pin dual channel relay, with 2 SPNO contacts
AutomationDirect
offers thousands of industrial automation products through its online superstore and 2,000-page catalog. Products include Programmable Logic Controllers (PLCs), AC drives/motors, operator interface panels/HMI, motor controls, DC power supplies, push buttons, sensors, NEMA electrical enclosures, wire duct, wire and more. The company offers high-quality automation products at savings up to 50%, along with detailed documentation and superior sales and technical support. Same-day shipping on in-stock items ordered by 4 p.m.
ET is standard. A 30-day, money-back guarantee is offered on most items, including software.Select the process controls and industrial wiring supplies you need from over 7,000 quality products, often priced well below the industry average. To request a free catalog, visit their Web site or call 800-633-0405.
