R310A Series Current Sensing Switch
Code No. LIT-1900005
Issued November 13, 2015
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
Selection Chart
Product Code Number Description
R310AD-1C Current Sensing Switch
Voltage switching capacity: 0 to 30 VAC
Used with: P445 Electronic Lube Oil Control
R310AE-2C Current Sensing Switch
Voltage switching capacity: 120 to 240 VAC
Used with: P28 and P45 Electromechanical Lube
Oil Controls
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 a
Technical Specifications
R310A Series Current Sensing Switch
Switch Action SPST, normally open
Current Sensing
Range
Switch Threshold R310AD-1C 0.5 Amperes
Sensor Supply Voltage Induced from monitored conductor,
Switching Capacity
(General Purpose)
Output Polarity Non-polarity sensitive output
Enclosure NEMA 1
Ambient Operating Conditions 5 to 140°F (-15 to 60°C);
Ambient Storage Conditions -40 to 158°F (-40 to 70°C);
Dimensions (H x W x D) 2.34 x 1.85 x 0.875 in.
Sensor Hole Size 7/10 in. (17 mm) Diameter
Agency Listings UL Guide NRNT
nuisance 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, co ntact the
nearest Johnson
R310AD-1C 0.5 to 200 Amperes
R310AE-2C 0.75 to 200 Amperes
R310AE-2C 0.75 Amperes
R310AD-1C 0.1A at 30 VAC/DC
R310AE-2C 0.5 at 250 VAC/DC
Controls®
isolation 600 VAC RMS
0 to 95% RH, noncondensing
0 to 95% RH
(59 x 46 x 22 mm)
cUL Guide NRNT7
representative.
The performance specifications are nomina l and conf orm to accep table industr y standar ds. For ap plications a t condition s beyond th ese specification s, consult the local Johnson Controls o ffice.
Johnson Controls, Inc. shall not be liable for damages resulting from misapplication or misuse of its products. © 2015 Johnson Controls, Inc.
www.johnsoncontrols.com
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