No matter what equipment is delivered, it shall be tested according to relevant design requirements, and it can only be delivered after it meets various standards. The same is true for MNS low-voltage drawer cabinet. What tests are required for its successful delivery? The manufacturer of MNS low-voltage drawer cabinet will introduce the four major steps of factory inspection of MNS low-voltage drawer cabinet for you. Interested friends can learn about it.
1、 Test preparation of MNS low-voltage drawer cabinet
1. Before powering on MNS low-voltage drawer cabinet or IO cabinet, all power switches must be cut off.
2. All connections between MNS or DCS cards and the outside must be cut off.
3. Check whether the power terminal wires and connecting devices are tightly crimped. False connection of the power line will cause the instrument or electrical appliance to burn.
4. Check whether the hardware settings of various instruments and electrical appliances are consistent with the design requirements; Check whether the power supply and circuit settings of the terminal board are consistent with the design requirements.
2、 Power-on detection of MNS low-voltage drawer cabinet
1. Principle: start from the main power supply to deliver power one by one. Before power transmission, check whether the voltage at the input side of the switch is normal and whether the impedance at the output side of the switch is normal. If the resistance at the output side is small, analyze the reason for confirmation. Multiple instruments in the cabinet are not allowed to be powered on at the same time. One instrument can be put into operation after it is powered on normally.
2. The manufacturer of MNS low-voltage drawer cabinet reminded everyone to confirm whether the AC voltage level meets the requirements before closing the main power supply. When there are two incoming lines of AC power supply and there is no automatic switching, strict attention shall be paid to avoid parallel connection. When there is automatic switching, no-load test shall be conducted to check whether the automatic switching device of dual power supply operates normally.
3. After the AC power supply is normal, power on the DC power supply. Check whether the output voltage of the DC power supply is normal and whether it is normally sent to the inlet side of each DC switch.
4. Check whether the DC power supply is sent to the terminals of all electrical equipment, including the power supply terminals of the MNS expansion module. After the inspection, the unused instruments can be temporarily closed to wait for the next test.
3、 Signal injection of MNS low-voltage drawer cabinet
When using the signal generator to inject signals into the instrument, it is necessary to clarify the nature of the injection point and the output type of the signal generator. The voltage signal is not allowed to inject into the current signal input terminal. AI input terminal shall inject corresponding signals into the instrument signal input terminal according to the signal type (2-wire system, four-wire system, voltage, resistance, mv, etc.). Selecting the wrong signal will cause the signal generator or instrument to burn.
4、 Precautions for MNS low-voltage drawer cabinet
1. When the instrument or MNS is electrified, it is not allowed to inject current signal on the current signal output terminal, which will cause the meter to burn.
2. It is not allowed to use the resistance gauge to measure the resistance or on-off of live equipment or components. Violation of this requirement will cause the resistance gauge to burn.
3. The resistance box is a kind of signal transmitter at the time of delivery. It can only be used as the analog resistance temperature signal source. It is not allowed to be used as a variable resistance for other tests at will.
4. When the ammeter is connected in series to the circuit to measure the current, it should be confirmed that the current range is selected as the appropriate gear.
In fact, it is normal for MNS low-voltage drawer cabinet to have some wrong wiring or wrong setting in the design process, but we should take effective measures to avoid as much as possible, and the above four steps can effectively avoid some problems and achieve the successful delivery of MNS low-voltage drawer cabinet. Come to our website for more relevant content http://www.tongyuhengcheng.com Ask!