what is the difference between a potential relay and a current relay?

Question

what is the difference between a potential relay and a current relay?

Answer 1

*Current Relays :



Current Type Motor Starting Relays are used for assisting in the starting function of single phase AC motors of resistance start, induction run; and capacitor start, induction run types. Generally, the size of the motor is limited to approximately 1/3 HP, 120 Volts AC and 3/4 HP, 240 Volts AC. The most common applications are household refrigerator and freezer compressors, automatic dishwasher motors, and automatic laundry motors.

*Features and Benefits :

Rugged, durable construction.

Quiet operation.

Long life electrical contacts.

Quick Connect Tab Terminals.

Optional spare terminals available .



* Potential Relays are used for assisting in the initial function of capacitor start, induction run and capacitor start, capacitor run motors. The motors are the larger sized compressor motors for residential central air conditioning systems and larger pump motors (over 1/3 hp at 120 VAC and 3/4 hp at 240 VAC). Smaller motors used on residential refrigeration systems generally use current type starting relays or thermal/resistance devices such as PTCR's. In order to use a potential type starting relay, the motor must have a start capacitor, but it may or may not also have a run capacitor.



*Features and Benefits of a potential relays:

Armature - Corrosion resistant armature seals to the magnet core on relay pickup, opening the relay contacts to disconnect the start capacitor.

Relay Coil and Magnet Core - Class "B" temperature-rated coil provides magnetic flux to operate armature at a specific motor speed.

Electrical Contacts - Large Silver/Cadmium Oxide snap-action contacts provide reliable disconnection of the start capacitor and long life.

Spare Terminals - Spare terminals are available for interconnections.

Terminals - Easy to access tin-plated brass quick-connect terminals provide reliable low-resistance connections to the application wiring. Screw-type terminals (not shown) are available.

Base - Rugged phenolic base material provides insulation and rigid support to the relay mechanism and terminals for consistent performance during life.

Cover - Durable phenolic cover encloses the relay and has provisions for several standard mounting brackets.

Answer 2

Potential Relay

Answer 3

I think what you mean to ask is; "The difference between a current sensing, and potential sensing relay. I ve never heard of a potential relay. Relays are "pulled in" by applying voltage to the coil, typically 120Vac, or 24Vdc. A current sensing relay will close its contacts when it is wired to sense a particular amount of current. Instead of applying voltage (turning on) the relay, it closes contacts when current flows through it.

HVAC technician

***** A current relay has a coil of low resistance wire (heavy gauge wire, few turns), and is energised only by a large current, such as the initial current of a motor starting. The relay coil is wired in series with the run/main winding of the motor, and the relay contacts are normally open. As the motor tries to start, the large current closes the relay, which momentarily brings the start/aux winding into circuit, allowing the motor to go. Used for split-phase and capacitor-start motors.

A potential relay has a coil of high resistance wire (light wire, many turns), and is wired in parallel with the start/aux winding, and the relay contacts are normally closed. At initial motor start-up, high curent will flow through both the run and start windings of the motor. As the motor reaches operating speed, the current reduces, and a "back EMF" is produced allowing current to now pass through the potential relay coil, and open the contacts. Used for capacitor-start and cap-start cap-run motors.

Another HVAC technician.

you sound like a real ahole. everyone in the field calls them potential relays, in addition look at a schematic on an AC and you ll find "PR" potential relay. what a dip#hit

Answer 4

Potential or “voltage” relays are used with single-phase capacitor-start/capacitor-run motors, which need relatively high starting torque. Their main function is to assist in starting the motor.



Current starting relays consist of a low resistance coil and a set of normally open contacts. The coil is wired between terminals L and M. The contacts are wired between terminals L and 2 when a start capacitor is used.

Answer 5

A 'current' relay has a coil of low resistance wire (heavy gauge wire, few turns), and is energised only by a large current, such as the initial current of a motor starting. The relay coil is wired in series with the run/main winding of the motor, and the relay contacts are normally open. As the motor tries to start, the large current closes the relay, which momentarily brings the start/aux winding into circuit, allowing the motor to go. Used for split-phase and capacitor-start motors.

A 'potential' relay has a coil of high resistance wire (light wire, many turns), and is wired in parallel with the start/aux winding, and the relay contacts are normally closed. At initial motor start-up, high curent will flow through both the run and start windings of the motor. As the motor reaches operating speed, the current reduces, and a "back EMF" is produced allowing current to now pass through the potential relay coil, and open the contacts. Used for capacitor-start and cap-start cap-run motors.



https://www.electrikals.com/products/r/relays?cid=690&page=1&pagesize=15

Answer 6

Briefly

A relay has two main components. The contacts (Normally open or normally closed) and the coil.

Now, a potential relay is one whose coil is set to be activated by voltage. Such kind of relays have voltage settings, for example at a voltage of 110V, the coil will be energised and the contacts will close or open.

A current relay is thus a relay whose coil is set to be activated by current levels.