Johnson Controls - R310AE-2C - Current Sensing Switch

R310A Series Current Sensing Switch

Description
The R310A Series Current Sensing Switch detects alternating current (AC) flow in a single circuit without being connected to that circuit. It may be used in any application where current detection is required.

The R310A replaces the R10A used with Johnson Controls/PENN® time delay oil failure cutout controls such as the P28, P45, and P445. These applications incorporate internal line breaking overload protection, where lockout due to overload cycling is unacceptable or undesirable. The R310A switch is not intended to detect breakage of belts.

The R310A is molded in a high dielectric material, which permits mounting inside a starter or contactor.

Refer to the R310A Series Current Sensing Switch Product Bulletin (LIT-121536) for important product application information.

Features

• small size allows mounting in small enclosure
• solid-state switching contains no moving parts to fail
• low 0.5 ampere activation allows monitoring of most small equipment circuit loads
• high 200 ampere monitoring capacity allows monitoring of heavy duty equipment
• large 0.70 in. (18 mm) diameter sensor hole accepts large diameter wire sizes and multiple coilings of smaller diameter wire sizes

Applications
The R310A Current Sensing Switch is designed to sense alternating current in a conductor that passes through its opening. The R310A sensor closes an electronic switch if the alternating current in the conductor exceeds 0.5 amperes. Thus, the R310A switch may be used for several purposes:

• switch a pilot circuit
• energize a run signal on a device such as a fan, motor, or pump
• monitor motors and electrical loads for proper operation
• monitor on/off status of process motors

The R310A Series Current Sensing Switch is available in two models. The R310AD-1 switch is for use in low-voltage applications, such as with the P445 Electronic Lube Oil Control. The R310AE-2 switch is for use in high-voltage applications, such as with the P28 and P45 Electromechanical Lube Oil Controls.

The R310A switch avoids nuisance lockouts by sensing the lack of current flow to the motor. Regardless of the reason for motor shutdown, the lube oil control time delay circuit is de-energized when the current flow in the motor supply line drops below 0.5 amperes.

In a typical application, the lube oil control does not lock out when the control circuit shuts off the compressor. However, if the compressor overheats and the internal thermal overload circuits open, the compressor shuts itself down, which causes the oil pressure to drop. This drop in oil pressure will energize the lube oil control heater (P28, P45) or timer (P445), causing anuisance lockout. In this situation, the R310 switch senses the lack of current to the motor, and is used to de-energize the time delay heater (P28, P45) or electronic timer (P445) before a nuisance lockout occurs.

Repair Information
If the R310A Series Current Sensing Switch fails to operate within its specifications, replace the unit. For a replacement switch, contact the nearest Johnson Controls® representative.