Extech CT20 Operating Manual

User's Guide

Continuity Tester Pro Model CT20

Introduction

Congratulations on your purchase of the Extech CT20 Continuity Tester Pro. The CT20 allows a single user to quickly identify and label two wires even when the wire ends are located in different rooms. This tester is shipped fully tested and with proper use will provide years of reliable service.

Safety

CAUTION: DO NOT CONNECT TO A LIVE CIRCUIT

Safety Precautions

1. Improper use of this tester can cause damage, shock, injury or death. Read and understand this user’s guide before use.

2. Ensure that the battery door is properly closed and secured before use.

3. Inspect the condition of the test leads and the tester itself for any damage before use.

4. Remove the battery from the tester if it is to be stored for a long period.

Description

1. Local Continuity Tester (main pulsing unit)

2. Local Continuity Indicator (flashing red LED)

3. Power On/Off (mini-slide switch)

4. Power “On” Indicator (steady green LED)

5. Local Continuity Beeper (with air holes on rear of case)

6. Remote Probe Continuity Indicator (red/green bi-color LED)

7. Remote Probe Holder (side mounted plastic piece)

8. Red and Black Remote Probe Leads w/alligator clips

9. Red and Black Tester Leads w/alligator

10. 9 Volt Battery Compartment (removable cover on rear)

Specifications

Power supply 9 Volt Battery Beeper 85dB beeper Battery life Approx. 12 months with normal use. Continuity confirmation Equal to or less than 2.0 K Ohms Continuity drive current: Pulsed (2.0 Hz) 20 - 50mA at 10 Ohms and 2.0mA -

Wire Verification Distance 10,000 Ft, 3,000 m (26 Gage min.) Fuse 250V 0.5A fast blow Operating Temperature 10 Storage Temperature -4 to 176 Operating Humidity 10 to 90% RH (non-condensing) Dimensions 3.6 x 2.2 x 1.14” (90 x 57 x 29mm) Weight 9.2oz (260g)

8.0mA at 1000 Ohms.

F to 113oF (-12 to 45oC)

F (-20 to 80oC)

Operation

CAUTION: DO NOT CONNECT TO LIVE WIRES. Use only on non-energized circuits

Remote Continuity

Remote continuity is a different mode of usage for the Tester and requires the Remote Probe. This mode is primarily used for: A. remote verification of continuity for cable/wires, or B. individual cable/wires for identification and labeling. Properly used, the Tester with Remote Probe will eliminate numerous trips when testing cable TV, electrical cables, and speaker/telephone wiring in multi-room/multi-floor installations.

1. Turn power on. The green

2. Attach red and black alligator

3. Proceed to the other end of the

4. If continuity exists, the LED on

5. When Tester (red lead) is connected through wire

6. Once correct orientation has been achieved

Advanced Remote Continuity and Wire Identification

The Remote Continuity mode can be used to check continuity and to identify two, three or more cables/wires simultaneously by applying simple logic and a testing strategy. To facilitate cable/wire identification, the leads of the tester and probe use matching color

power LED will glow. If green LED fails to light replace 9V battery.

clips of Tester to one end of cable/wires under test.

cable/wires and connect them to Remote Probe test leads.

the probe will flash either green or red depending on the Probe leads orientation. Note: At this point, Tester hanging on cable/wires at origination end, will beep and flash red while remote probe (with user) at destination end is verifying continuity.

under test to Remote Probe (red lead) and Tester (black lead) is connected through wire under test to Remote Probe (black lead), then Probe LED flashes green indicating correct connection orientation. If Probe LED flashes red, this indicates Probe Leads are not correctly connected. Reverse probe leads to produce green light.

(flashing green LED), then wires under test can be labeled consistent with the colors on tester and probe leads.

Local Continuity

Using just the tester (without probe) you can easily test any in-wall wiring from point to point locations in the same room. Other handy uses are to quickly test light bulbs, fuses, switches, relay contacts, diodes, low ohm power resistors, circuit breakers, etc. for electrical continuity.

1. Turn power switch on. The green power LED will glow. If green LED does not light, replace 9V battery.

2. To check same room wiring runs, attach both red and black alligator clips of Tester to both wires on one end of multi-wire cable under test and let Tester hang from wires.

3. Go to other end of same cable and momentarily connect wires in cable together. The Tester will beep and red LED will flash indicating continuity.

4. When continuity is found, label both ends of cable with the same number or name.

5. To test other devices (listed above) connect Tester leads to device terminals in any* lead orientation (red or black). If device makes internal electrical connection then Tester will beep and its red LED will flash indicating continuity.

*Exception: When testing a diode, the red Tester lead is positive and will show continuity when connected to the anode (positive (+) side) with black Tester lead to cathode (negative (-) side).

Battery replacement

1. Loosen Phillips head screw of battery compartment and remove cover (rear).

2. Replace 9 volt battery and compartment cover, then tighten screw.

Disposal

Follow the valid legal stipulations in respect of the disposal of the device at the end of its lifecycle

CT20 V4.0 11/06