Honeywell CTS-20, CTP-20 User Manual

Solid Core and Split Core 4-20 mA

WARNING

CAUTION

CAUTION

Output Current Sensors

CTS-20; CTP-20

INSTALLATION INSTRUCTIONS

SAFETY

For CTS-20 Series current sensors, ensure
that all power sources are disconnected and
locked out before installation as severe injury
or death may result from electrical shock due
to contact with high voltage wires.

This product is not intended to be used for life
or safety applications.

This product is not intended for use in any
hazardous or classified locations.

INSTALLATION

Make sure that all installations are in compliance with all
national and local electrical codes. Only qualified
individuals that are familiar with codes, standards, and
proper safety procedures for high-voltage installations
should attempt installation. The current sensor is a 2­wire, 4 to 20 mA Loop Powered device that requires a
regulated +12 to 30 Vdc external power source.

IMPORTANT

The current switch should be used on insulated
conductors only!

The current sensors may be mounted in any position
using the two (2) #8 x 3/4 in (19 mm) Tek screws and the
mounting holes in the base or snapped directly on to the
1-3/8 in. (35 mm) DIN rail (See Figures 3 and 4). Leave a
minimum distance of 1 in. (25 mm) between the current
sensor and any other magnetic devices such as
contactors and transformers.

3X

Fig. 1. Sensor placed on DIN rail

3X

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M25289

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IND.CONT.EQ.

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M25290

Fig. 2. Sensor removed from DIN rail

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SOLID CORE AND SPLIT CORE 4-20 MA OUTPUT CURRENT SENSORS

WARNING

CAUTION

Latch Operation (Split Core Models)

Pressing down on the two (2) side tabs and swinging the

The secondary of the 5A Current Transformer
(C.T.) must be shorted together before the
power may be turned on from the device.

For applications in which the normal operating current is
greater than 200 or 250 Amps, depending on the model,
or for conductor diameters larger than 0.75 in. (19 mm) in
diameter, an external 5 Amp Current Transformer (C.T.)
must be used in conjunction with a CTS20-005 or CTS20­005VFD as shown in Fig. 5.

INSULATED CONDUCTOR

600:5 RATIO 5A C.T.

WIRE NUT

cover open, opens the split core current switch as shown
in Fig. 6. Lifting up the latch with a flat-tip screwdriver as
shown in Fig. 7 can also open the unit. Press down firmly
on the cover to close the current switch. An audible “click”
will be heard as the tab slides over the tongue on the
base.

Mating surfaces of the magnetic core are
exposed when the sensor is open. Silicone
grease, present on the cores to prevent rust,
can capture grit and dirt if care is not
exercised. Operation can be impaired if
anything prevents good contact between pole
pieces. Visually check the mating parts of the
core before closing the current sensor.

EXAMPLE: FOR CURRENTS UP TO 600 AMPS, USE A 600:5 RATIO C.T.
AS SHOWN.

Fig. 3. Current transformer

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Fig. 4. Opening sensor by hand

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M25299

Fig. 5. Opening with a screwdriver

M25295A

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Wiring

Honeywell recommends the use of 16 to 22 AWG (1.3 to

2

) shielded cable, copper wire only for all current

0.3 mm
sensor applications. A maximum wire length of less than

98.4 feet (30 meters) should be used between the current
sensors and the Building Management System or
controller.

NOTE: When using a shielded cable, be sure to connect

only (1) end of the shield to ground at the
controller. Connecting both ends of the shield to
ground may cause a ground loop.

When removing the shield from the sensor end, make
sure to properly trim the shield so as to prevent any
chance of shorting. The current sensor terminals are
polarity sensitive and represent a linear and proportional
4 to 20 mA output signal. The current sensors are
available in either an Average or True RMS output
version. The recommended torque to be used on the
terminal block connections is 5.93 in-lbs (0.67 Nm). The

M25298

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