UNIT-T UT18A Voltage and Continuity Tester

PRODUCT INFORMATION

Symbols referred in the manual

• The manual includes necessary information regarding the safe usage and equipment maintenance and, before use, read through each section of the manual.
• Failure to read the manual or comprehend the equipment use method specified in the manual would lead to physical injury and equipment damage.

OVERVIEW

Symbol on tester panel and its description (Figure 1)

1. Test pen L 1;
2. Test pen L2;
3. Voltage indication (LED);
4. LCD display;
5. High-voltage indication;
6. AC indication;
7. Continuity indication;
8. Polar indication;
9. Rotary phase indication;
10. RCD indication (LED);
11. RCD test button;
12. Flashlight/self-inspection button;
13. HOLD mode/backlighl button;
14. Flashlight
15. Test pen cap;
16. Battery cover

LCD panel

Figure 2 provides detailed description of LCD panel.

1. Silent mode indication;
2. HOLD mode indication;
3. Low-voltage battery indication;
4. Voltage measurement;
5. Frequency measurement;
6. DC voltage measurement
7. AC voltage measurement;
8. Voltage indication (LCD segment code);
9. High-voltage indication;
10. Continuity indication;
11. RCD indication;
12. Rotary phase indication

Operation instruction

Operation instruction and use scope of the tester

Voltage and continuity tester includes four models: UT18A, UT18B, UT18C, UT18D and UT18E, has such functions as AC/DC (including three-phase alternating current) voltage measurement, three-phase AC phase indication, frequency measurement, RCD test, continuity test, the simple test in case of no battery power supply, self-inspection, silent mode choice, overvoltage indication and low-voltage battery indication. In addition, the flashlight attached to the test pen provides convenient application in a dark environment. To protect tester and, more particularly, the tester user, the tester is equipped with protecting jacket. The tester should be put on a protective jacket after use and, preferably, placed inside tool kit so as to protect it against any damage. Never place the tester into your pocket.

The tester is applicable to various occasions such as the household, factory, electric power department, etc.

It has the following characteristics:

1. To protect against physical injury, ii is designed with a protective jacket.
2. LED indication (UT1 BA/B/C/E);
3. LCD voltage and frequency display (UT18C/D/E);
4. AC/DC measured up to 690V, UT18E can reach 1000V;
5. Continuity measurement;
6. Indicate the phase relationships among three-phase AC;
7. Both the buzzing and silent mode is optional.
8. Detection without battery (UT18A/B/C/E);
9. Flashlight function;
10. Self-inspection function;
11. Low-battery voltage indication and measured voltage over range indication (When the UT1 BE is low-battery voltage, it cannot be measured and needs to replace the battery);
12. RCD test (UT18B/C/D/E);
13. Automatic standby.

Safety precautions

To prevent physical injury, electric shock or fire, pay special attention to following items:

• Before using a voltage detector with audible indicator at locations with a high background noise level, it has to be determined whether the audible signal is perceptible.
• The voltage detectors are designed to be used by skilled persons and in accordance with safe methods of work.
• The different indicating signals of the voltage detector (including the ELV limit indication) are not to be used for measuring purposes.
• Be sure both the test pen and test instrument is intact before test;
• Be sure keep your hand only in contact with the handle while using the equipment.
• Never use the equipment while the voltage is beyond the range (referring to technical specification parameters) and above 800V;
• Before use, be sure the equipment can function well;
• To ensure normal operation of tester, measure a known voltage value in first.
• The tester cannot be used any more in case of one or several functional failure(s) or no functional indication.
• Never test in wet conditions.
• Display functions well only when the temperature ranges -15″+45″C and relative humidity is <85%.
• The instrument must be repaired in case the personal safety of operator cannot be guaranteed.
  1. The safety would no longer be guaranteed in any of the following circumstances:
  2. Visible damage;
  3. Tester’s functions are inconsistent with the functions that it is supposed to have.
  4. It had been stored in inappropriate conditions for a long time.
  5. Subject to mechanical extrusion in transit.

Voltage measurement

A Observe safety test regulations specified in item 3. Voltage gear of tester is composed of a line of LED or LCD segment codes, including 6V (IJT18D), 12V, 24V, 50V, 120V, 230V, 400V, 690V and 1000V (UT18E only). LED (or LCD segment code) would be lighted one after another along with increased voltage, and so will the polarity LED (or LCD segment code) indication, AC LED (or LCD segment code) indication, on-off LED (or LCD segment code) indication, RCD LED (or LCD segment code) indication, rotary phase LED (or LCD segment code) indication and high-voltage LED (or LCD segment code) indication.

1. Complete a self-check of tester before test. After pressing the flashlight key 5s, tester would perform ACIDC full range detection, accompanied by flashing LED (with the exception to RCD light) and blinking displayed LCD. If need to exit self-check, just touch the flashlight key. Connect two test pens to the conductor to be measured, select a known voltage for measurement, such as 220V socket, and ensure the measurement accuracy (See Figure 3). The tester cannot measure AC and DC voltage less than 5V and provides no accurate indication while measuring voltage is 5Vac/dc. Illuminating continuity light or AC light or high-voltage symbol (UT18D) and beeping buzzer are normal.
2. Tester would provide LED indication (UT18A/B), LED•LCD indication (UT18C/E ) and LCD indication (UT18D) while measuring AC or DC voltage. High-voltage LED would be illuminated and buzzer beeps when the measured voltage is extra low voltage (ELV) threshold. measured voltage continues to increase and exceed input protection voltage (UT18A’B/C/D:750Vac/dC, UT18E: 1015Vac/dc) Of the tester, the corresponding LED would keep flashing (UT18A/B/C/E), LCD displays “OL’ (UT18C/D/E ) and the buzzer keeps beeping.
3. For measuring DC voltage, if L2 and Ll connected respectively to the positive and negative pole of the object to be measured, LED would indicate the corresponding voltage, LCD displays the voltage, meanwhile the LED indicating positive pole would be illuminated, LCD displays “VDC” and, on the contrary, the LED indicating negative pole would be illuminated, LCD displays “-NDC”. If need to judge the positive and negative pole of the object to be measured, connect two test pens to the object to be measured randomly, the illuminating positive pole LED or LCD “+” on tester means the terminal connecting to L2 is the positive and the other connecting to Ll is the negative.
4. For measuring AC voltage, two test pens may be randomly connected to two ends of the object to be measured, AC LED would be illuminated ( “+” , “-” LED illuminate indicate AC at the same time, only for UT18E) LCD displays “VAC” while LED indicates the corresponding voltage value and LCD displays corresponding voltage value.

Note: For measuring AC voltage, L and R phase inversion indication LED (UT18A/B/C/E) or L and R symbol (UT18D) would be illuminated, it means phase indication is unstable, L light (L symbol) or R light (R symbol) is illuminated, and even L and R light (L and R symbol) would be illuminated alternatively; L and R light (L and R symbol) would not provide correct and stable indication unless measunng three phase power system.

Detection without battery

The tester may perform simple detection while the battery runs out or not battery is provided. Connect two test pens to the object to be measured. When the object has a voltage higher than or equivalent to 50V AC/120V DC, high -voltage LED would be illuminated, indicating dangerous voltage and the LED would gradually brighten along with increased voltage to be measured. The function is applicable only to UTI BAJB/C/E.

Continuity test

To confirm if the conductor to be measured is electrified, voltage measurement method may be adopted to measure the voltage at both ends of the conductor by using two test pens. Connect two test pens to the both ends of the object to be measured, if the resistance falls within continuity symbol ” (UT18D) would be illuminated, accompanied by continuous beeping buzzer; and if resistance falls within 100kQ—150kQ, continuity LED(LJTI 8N3/C)or continuity symbol “ ” (UTI 8D)may or may not be illuminated and buzzer may or may not beep; if the resistance falls within LED(UTI 8E)or continuity symbol ” ” would be illuminated, accompanied by continuous beeping buzzer: if resistance falls within 60kQ—150kQ. continuity continuity symbol may or may not be illuminated and buzzer may or may not beep if resistance is >150kQ, continuity LED(UTI 8A/B/C/E) or continuity symbol “” (UT18D) may not be illuminated and buzzer would not beep. Before any test, be sure the object to be measured red is not electrified.

Rotation test (three-phase AC phase indication)

• The measurement must be conducted in accordance with the safety test regulations specified in item 3.
• ln the case Of strong electric field interference or strong radiation test phase sequence, the test results may be unstable.

R, L LED or L and R symbol indication is applicable for rotation test and the test is only applicable for a three-phase AC system.

1. Three-phase voltage test range: 57VÄ400V (50Hzæ60Hz) (IOOV—400V only for UT18E).
2. Hold the main body of tester (with finger holding handle), as shown in the following figure, connect test pen L2 to any phase and Ll to any of the remaining two phases.
3. R or L LED would be illuminated, and after connecting a test pen to another phase, another LED (L or R) would be illuminated.
4. L or R LED would be illuminated accordingly when the position of two test pens are exchanged.
5. LED would indicate the corresponding voltage or LCD displays the corresponding voltage value, the indicated or displayed voltage should be phase voltage against earth but the three-phase voltage.

Diagram of three phase electric system testing (Figure 4)

Note: For measuring three-phase AC system, connect three measuring terminals to the corresponding terminal of three-phase system and, since the tester has only two test pen terminals, it is required to form the reference terminal by holding tester handle with finger {through the ground}, therefore it would not accurately indicate the phase sequence of three-phase system if not holding the handle or wearing insulating gloves. In addition, it is necessary to ensure the earth terminal (earth wire or shell) of three-phase system in contact with human body while measuring three-phase power system lower than 1 DOV.

RCD test

To reduce disturbance voltage during voltage measurement, a circuit with impedance lower than the tester under normal measurement mode may be provided between two test pens, namely the RCD circuit system. For RCD trip test, connect two test pens to the Land PE terminal of 230Vac system under normal voltage measurement mode and press RCD key”}” on two test pens, RCD system would trip and the LED indicating RCD(UT1BB/C/E)or RCD symbol {UT1 BD) would be illuminated if the circuit then generates AC current higher than 30mA. Particularly, if RCD cannot measure for a long time and, at 230V, the testing time should be <1 Os, cannot conduct continuous measurement and, after once test, wait 60s before next measurement.

Note: In case of no measurement or test, it is normal to have a continuously illuminated LED and a continuous beeping buzzer after simultaneously pressing RCD keys on two test pens. To avoid functional disorder, do not press two RCD keys under non-RCD testing mode.

Silent mode selection

It is allowed to enter the silent mode while tester is under standby mode or normally used. After pressing flashlight key about 1 s, tester would bleep and LCD displays silence symbol “” (UT1 BC/D/E), and tester enters silent mode and, under which mode, all functions are similar to those under normal mode, with exception to the silent buzzer. If need to resume normal mode (buzzing mode), press flashlight key about 1 s and, after “bleeps”, the silence symbol “” on LCD would disappear.

Application of flashlight function

Flashlight function may be selected if need to use the tester at night or in a dark environment; after light touch on flashlight button on tester panel, the headlamp on the top of tester would be turned on to facilitate your operation and, after operation, turn off the light with a light touch on the button.

Application of backlight (only applicable for UT18D)

LCD displayed data may be hard to read at night or n a dark environment, allow the display clearly visible by turning on backlight on tester. Backlight would be turned on after pressing HOLD about 1 s and, after operation, turn off the light after pressing HOLD about 1 s. If tester enters standby mode while backlight is on, the light would remain illuminated when tester is awakened. The backlight cannot be turned off unless pressing HOLD about 1 s again.

Application of HOLD function (UT18C/D/E)

To facilitate reading and recording, hold the measured data (voltage and frequency value) by a light touch on HOLD on tester while using tester; after another light touch, hold status is relieved and restores to normal testing status.

Battery replacement

Before using the voltage detector ,Touch and hold the two probe tips together. If I shows and you hear the beeper, or in the silent mode, I is on. This makes sure that the battery source is not exhausted. otherwise, the battery source is exhausted. Continuously flashing negative LED (UT1BA/B) or low-voltage symbol on LCD (UT1BC/D/E) during use of tester indicates low-battery voltage and the necessity of battery replacement.

Replace battery according to following procedures (as shown in Figure 5):

• Stop measurement and disconnect two test pens from the object measured;
• Screw out screws securing battery cover with screwdriver;
• Remove battery cover;
• Take out the battery to be replaced;
• Install new battery according to the battery symbol and direction indicated on panel; and
• Insert battery cover and secure it with screws

Warning:

To avoid electric shock, make sure the probes are disconnected from the measured circuit before removing the rear cover. Make sure the rear cover is tightly screwed before using the instrument.

Note: For environmental protection, batteries may be collected and recycled at fixed collection point while disposing the disposable battery or accumulator containing hazardous waste. Please follow the local valid recycling regulations and dispose of the batteries replaced as per disposal rules for old battery and accumulator.

Equipment maintenance

No special maintenance requirement is provided unless UT1 BA/B/C/D/E tester should be used as per manual instruction and, in case of any functional abnormality during normal operation, stop using immediately and contact the nearest authorized service center.

Equipment cleaning

Before cleaning, disconnect tester from the circuit being tested. If the instrument gets dirty during normal use, wipe it with wet cloth or small quantity of gentle household cleanser instead of acid cleanser or solvent. Do not use the tester within 5h after cleaning.

Technical indicator

Waterproof	lp65	√	√	√	√	√
Auto range	Full range	√	√	√	√	√
Flashlight	Full range	√	√	√	√	√
Low-battery voltage indication	About 2.4V	√	√	√	√	√
Over voltage protection	About 750V	√	√	√	√	(1015V only for UT18E)
Auto standby	Standby current <1OuA	√	√	√	√	√
Silent mode	Full range	√	√	√	√	√
Backlight	Full range				√
LCD display (voltage)	6V~690V			± (-1 5%+1)	± (-1 5%+1)	±(1.5%+1) ( 100 0 Vo nly for UT18E)
LCD display (frequency	40Hz~400Hz			±(3%+5)	±(3%+5)	±(3%+5)

LCD display accuracy indicator:

Range (AC/DC)	6V	12V/24V	50V	120V	230V/400V/690V	1000V
UT18C	±(1.5%+1)	±(1.5%+2)	±(1.5%+3)	±(1.5%+4)	±(1.5%+5)
UT18D	±(1.5%+1)	±(1.5%+2)	±(1.5%+3)	±(1.5%+4)	±(1.5%+5)
UT18E	±(1.5%+1)	±(1.5%+2)	±(1.5%+3)	±(1.5%+4)	±(1.5%+5)	±(1.5%+5)

Parameter

Function and parameter description

• LED voltage range: 12V-690V AC/DC, 1000V AC/DC (only for UT1 BE)
• LED voltage indication point: 12V, 24V, 50V, 120V, 230V, 400V, 690V, 1000V (only for UT1BE)
• LCD voltage range: 6V-690V AC/DC(UT1 BC/D), 1 000V AC/DC (only for UT1 BE); resolution: 1V, voltage accuracy: ±(1.5%+1-5 Digits);
• Frequency measurement range: 40Hz-400Hz, resolution: 1 Hz, accuracy: ±(3%+5Digits)
• Voltage measurement: Auto
• Buzzing and silent mode is optional;
• Polarity indication: Auto
• Range selection: Auto
• Response time: LED<0.1 s/LCD<1 s
• Peak current of test circuit: ls<3.5mA (ac/dc)
• Test time: 30s
• Recovery time: 240s
• RCD test: Range: 230V (50Hz-400Hz); Current: AC30mA~40mA; Test time <1 Os, recovery time: 60s;
• Over voltage protection: 750V AC/DC (1015V AC/DC only for UT1BE)
• On-off test: 0 kΩ … 100kΩ (0KΩ …. 60KΩ only for UT1BE); Accuracy: Rn+50%;
• Rotation test (three-phase AC) Voltage range: 57V-400V; Frequency range: 50 Hz~60Hz (1 00V-400V only for UT1 BE);
• Simple test (without battery) Voltage range: 50VAC ~ 690VAC, 120VDC- 690VDC (UT1BA/B/C, 1000Vonly for UT1BE);
• Working temperature range: -15″C~+45’C
• Storage temperature range: -2o·c-+60″C
• Working humidity range: :SB5% RH
• Over voltage protection class: CAT Ill 690V,CAT IV 600V,( UT1BE: CAT Ill 1000V,CAT IV 600V)
• Class of pollution: 2
• Safety rules: IP65, EN61010-1, EN61243-3:2010
• Weight: 23Bg (UT1 BA),272g(UT1 BB/C),295g(UT1 BD) ,277g(UT1 BE) (inclusive of battery);
• Dimensions: 272xB5x31mm
• Battery: IEC LR03 (AAA) x 2

Documents / Resources

UNIT-T UT18A Voltage and Continuity Tester [pdf] Instruction Manual UT18A, UT18B, UT18C, UT18D, UT18E, UT18A Voltage and Continuity Tester, UT18A, Voltage and Continuity Tester, Continuity Tester

References

• User Manual