Table of Contents
Advertisement
Quick Links
Advertisement
Table of Contents
Summary of Contents for FLIR Extech Instruments CT70
- Page 1 User's Guide AC Circuit Load Tester Model CT70...
- Page 2 Introduction Congratulations on your purchase of the CT70 AC Circuit Load Tester. This device can detect circuit and wiring problems such as: Poor ground impedance, false grounds, missing ground fault protection, low voltage availability under load, and high ground-to-neutral voltage. In addition, the CT70 tests GFCI and EPD circuits. Circuit and wiring issues listed above can introduce shock hazards (from grounding issues) and can comprise performance of machinery and equipment (from poor ground impedance, lack of sufficient voltage under load and/or high ground-to-neutral voltage).
- Page 3 Description Meter Description 1. AC power cable connection 2. Measurement results menu 3. Hot-Neutral-Ground coded measurement result 4. Primary reading display 5. Secondary reading display 6. Down arrow button 7. Right arrow button 8. GFCI test button Display Description Amperes (Current) Voltage Voltage Drop Percent Voltage Drop...
-
Page 4: Operation Overview
Operation Overview The CT70 AC Circuit Load Tester can test outlets or circuits under load for proper wiring, reverse polarity, and the presence of a ground. The CT70 uses a simple menu-driven display to allow the user to quickly see line voltage, voltage drop under full load, ground-to- neutral voltage, and line impedance. - Page 5 The Voltage menu displays the True RMS line voltage. Use the ► button to scroll the Voltage sub-menu (line voltage, ground-to-neutral voltage, Peak Voltage (P), and Frequency (Hz)). The Voltage Drop (Vd) window indicates percent voltage drop (with 15A load) and the Loaded Voltage (Vl).
-
Page 6: Testing Procedures
Testing Procedures Test 1: Wiring Verification The wiring configuration is the first test result that is displayed. Refer to the table presented earlier in the user guide for the test result key. For wiring conditions other than normal, the CT70 is limited in the type of tests it can perform on a circuit until the circuit’s wiring issues are resolved. - Page 7 Test 3: Voltage Drop Measurements To determine voltage drop, the CT70 measures line voltage, factors in the load, measures the loaded voltage, and then calculates the voltage drop. Results for 12A, 15A, and 20A loads are provided. For nominal efficiency, a voltage drop of 5% is the maximum recommended by the National Electrical Code (NEC) board.
- Page 8 Test 5: Impedance (Z) Measurements The impedance measurement capability of the CT70 is used to check Hot and Neutral impedance when voltage drop measurements are too high (greater than 5%). To determine where the problem is, measure the impedances and analyze the data as follows: •...
- Page 9 Test 6: GFCI (Ground Fault Circuit Interrupter) Testing A ‘GFCI’ can protect personnel from shock hazards. The CT70 tests GFCI circuits by forming a Hot-Neutral imbalance, leaking small amounts of current (6 to 9 mA) from Hot to Ground through a fixed resistance. A good GFCI circuit will sense this imbalance and switch off the power.
- Page 10 Test 7: EPD (Equipment Protective Device) GFCI Testing An EPD device can protect equipment as well as personnel. The CT70 tests EPD circuits by forming a Hot-Neutral imbalance, leaking current from Hot to Ground through a fixed resistance. A larger amount of current (30mA) is used than would normally be used to test a standard GFCI (6 to 9mA).
-
Page 11: Specifications
Specifications Measurement Specifications Range and Resolution Accuracy Line Voltage 100.0 to 250.0 VAC ± (1.0% + 0.2V) Peak Line Voltage 121.0 to 350.0 VAC ± (1.0% + 0.2V) Frequency 45.0 to 65.0 Hz ± (1.0% + 0.2Hz) Voltage drop (%) 0.1 to 99.9% ±... -
Page 12: Maintenance
Warranty EXTECH INSTRUMENTS CORPORATION (A FLIR COMPANY) warrants this instrument to be free of defects in parts and workmanship for one year from date of shipment (a six month limited warranty applies to sensors and cables). If it should become necessary to return the instrument for service during or beyond the warranty period, contact the Customer Service Department at (781) 890-7440 ext.
Need help?
Do you have a question about the Extech Instruments CT70 and is the answer not in the manual?
Questions and answers