How to measure the quality of the heat trace with a multimeter

Measurement method: 1. Problems such as short circuit, leakage and electric semi-tropical resistance that may exist in wiring, terminal wire, and wiring between strips. Insulation resistance is carried out in the following process.

The detection is OK, and the insulation meter is used to measure the insulation of the two wires to the ground respectively, and the resistance is heated.

It means that it is good.

Measuring principle: 2. Heat tracing.

Between the two wires is a resistive conductive rubber, which conducts electricity and heats up. This equates to a number of resistors connected in parallel between the two wires, and the longer the heat belt, the smaller the resistance between the two wires and the longer the area of heat. Checking the quality of the electric heat is that the electricity is on, and its heat is good.

3. Insulation inspection should be carried out before the use of the electric belt, less than 5 trillion ohms.

It must be replaced, otherwise the power switch will be tripped if the leakage is large. When laying the electric belt, the end of the electric belt that is not connected to the power supply should be cut in the middle, and the insulation tape should be used for insulation and bandaging, and it is best to use high-voltage insulating self-adhesive tape to wrap it, which can be used for 10 years in general.

Measuring the Heat Tracing in Detail:

How to measure the resistance of an electric heat tracing.

1. In the actual use of electric heat tracing, the resistance of the electric heat trace needs to be measured before installation, so how to measure the electrical heat resistance. Temperature-controlled electric heat tracing insulation resistance detection, mainly to detect whether the electric heat tracing is damaged, as well as the wiring of wiring, terminal wire, belt and belt wiring may exist short circuit, leakage and other problems.

2. Insulation resistance detection is required in the following processes:

1) Preliminary inspection: as mentioned above, before the installation of the electric heat tracing;

2) Acceptance test: before the installation of electric heat tracing and accessories is completed and the insulation is maintained;

3) Final test: This test is carried out before the insulation is completed and the system is energized.

3. When measuring the insulation resistance, use an insulation tester with a minimum voltage of DC500 V and a maximum test voltage of DC1000V, no matter how long the system is, and the insulation resistance should be at least 10 Mohm per heating circuit.

1) Electrical Heat Tracing with Protective Braids and Jackets: Measurements are taken between each electric heat tracing conductor and the protective braid, as well as between the protective braids and the grounding pipe.

2) Electric heat trace without braided sheath: Measurement is made between each power wire of the electric heat trace and the grounded pipe or thermally insulated grounding steel sleeve.

4. Precautions when measuring the insulation resistance of temperature control electric heat tracing.

When measuring insulation resistance, read from right to left, 0 on the right and 0 on the left.

The higher the insulation resistance value is to the left ( ) the stronger the insulation, and the more to the right (0) the worse the insulation. (The higher the insulation resistance measurement) is in m.

When the electric heat trace is installed in the usable area, it should be tightly bandaged with an end cap after being cut off.

The electric heat trace should have no outer skin damage at the tail end, and it is strictly forbidden to enter the water after it is cut off.

It mainly depends on whether to measure the on-off of the heat tracing, or the expected current value of the on-off of the power supply, and the power supply should have an experimental button for leakage protection. The on-off of the self-limiting temperature trace can be measured on and off with two wires on the side of the multimeter. The electric heating equipment is used to convert electrical energy into heat energy, and the heat lost by the heating equipment through the insulation material is supplemented through direct or indirect heat exchange, and the temperature control is used to track and control the temperature of the medium in the heating equipment, so that it can be maintained at a reasonable and economical level.

The electric heat can be cut short and used arbitrarily, but it can only be extended arbitrarily within a certain length range; The maximum service length is related to the rated voltage, power specification and the minimum ambient temperature at the time of use. If the length required to be used exceeds the maximum length of the electric heater, a separate power supply or an extra-long heat trace cable of special specifications should be used. Additional Information:

The DC current level of the multimeter is a multi-range DC voltmeter. The voltage range can be extended by parallel connection of the meter with a closed-circuit divider. The DC voltage level of the multimeter is a multi-range DC voltmeter.

The voltage divider resistor can be extended by connecting the voltage divider in series at the meter head. Depending on the voltage divider, the corresponding range is also different. The head of the multimeter is a magnetoelectric measuring mechanism, which can only use direct current, and use diodes to change AC to DC, so as to realize the measurement of alternating current.

The temperature control electric heating cable has an automatic adjustment of the output power of the heating system, so it will not burn out due to its own heating, but compensate for the actual need for heat, so it is a new generation of energy-saving thermostatic heater. The low temperature state is quickly started, the temperature is uniform, and each part can be automatically adjusted according to the temperature change of the heating place. When the temperature of the core band rises to the corresponding high resistance region, the resistance is so large that it almost blocks the current, and the temperature of the core band will reach the high limit and no longer rise (i.e., automatic temperature limiting).

At the same time, the core belt transfers heat to the cooler heated system through the sheath, and the heat transferred per unit time when it reaches steady state is equal to the electrical power of the cable. The output power of the cable is mainly controlled by the heat transfer process and the temperature of the heating system.

Electric heat tracing pipe insulation has become a thermal insulation and heating tracing product for winter frost protection of pipes and storage tanks and other equipment on many projects. It should be applied according to the different electric heat tracing products corresponding to different manufacturers. We have a lot of processes before leaving the factory for electric heat tracing, and inspect and test the product quality of electric heat tracing to ensure the quality of electric heat tracing, but in the process of transportation and installation, due to non-standard installation on site, it may lead to product problems, which will bring inability to the whole system, so after the installation is completed, it is necessary to test the electric heat tracing, and we commonly use the multimeter to judge whether the electric heat tracing is damaged through the multimeter.

The use of a multimeter is mainly to measure the resistance value of the electric heat tracing, through the resistance value to judge the quality of the electric heat tracing, to judge whether it is damaged, the use of the electric heat trace detection is divided into the following steps: 1After receiving the electric heat tracing, it needs to be tested with a multimeter to check whether the electric heat trace will be damaged due to transportation.

2.After the installation is completed, the electric heat tracing and system testing are carried out to ensure that the external insulation is applied.

OK. 1. Check whether the surface of the electric heat trace is damaged, and carry out it before installing the electric heat tracing;

2. The electric heat trace is consistent with the design requirements of all the matching parts, and is carried out before installing the insulation system;

3. After the insulation inspection is completed, it is carried out before powering on.

For the actual measurement of insulation resistance, use an insulation tester with a minimum voltage of 500 V DC and a maximum test voltage of 1000 V, regardless of the length of the system, with a minimum of 10 mohm per heat trace circuit of the insulation resistance.

1. Electric heat tracing with braid and outer sheath: Measurement is made between each electric heat tracing conductor and braid, and the local start is measured between the protective braid and the grounding wire at the same time.

2. Electric heat tracing without braid and outer sheath: Measurement is carried out between the power wires and grounding wires or thermally insulated grounding steel sleeves of electric heat tracing.

Answer 1: There may be problems such as short circuit, leakage and electric semi-tropical resistance in wiring, terminal wire, and wiring of strips. In the following process, the insulation resistance can be detected, and the insulation meter is used to measure the insulation of the two wires to the ground respectively, and the resistance heating means that it is good.