PROTECTIVE FUNCTIONS
Daily and Periodic Inspection
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Inspection |
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Inspec- | Description |
| Method | Criterion | Instrument | ||||
Item | Daily | 1 | 2 | ||||||
tion |
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| Disconnect cables |
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| from inverter and |
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| Inverter |
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| measure across |
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| module, | Check resistance |
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| { | terminals R, S, T, P, N | (See the following | Analog tester | |
| Converter | across terminals. |
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| and U, V, W, P, N <L1, | pages) |
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| module |
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| L2, L3, +, |
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| W, +, |
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| Ω |
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| range of 100 . |
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| (1) Check for liquid | { |
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| (1), (2) Visual check. | (1), (2) No fault. |
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| leakage. |
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| (3) Measure with | (3) 85% or more |
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| (2) Check for safety | { |
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| capacity meter. | of rated capacity. |
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| Smoothing | valve projection and |
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| Capacity | |
Main | capacitor | bulge. |
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| meter | |
| (3) Measure |
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circuit |
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| electrostatic |
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| capacity. |
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| (1) Check for chatter |
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| (1) Auditory check. | (1) No fault. |
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| Relay | during operation. |
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| (2) Visual check. | (2) No fault. |
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| (2) Check for rough |
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| surface on contacts. |
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| (1) Check for crack in |
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| (1) Visual check. | (1) No fault. |
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| resistor insulation. |
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| Cement resistor, | (2) Error should |
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| (2) Check for open |
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| be within | Tester, digital | ||
| Resistor | cable. |
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| resistor. | ± 10% of | ||
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| multimeter | |||||
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| (2) Disconnect one | indicated | ||
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| end and measure | resistance |
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| with tester. | value. |
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| (1) Check balance of |
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| (1) Measure voltage | (1) |
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| output voltages |
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| across inverter | phase voltage |
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| across phases with |
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| output terminals | balance within |
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Control |
| inverter operated |
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| 8V for 400V. | Digital | ||
circuit | Operation | independently. |
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| (2) Simulatively | (2) Fault must | multimeter, | |
Protective | check | (2) Perform sequence |
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| connect or | occur because | rectifier type | |
circuit |
| protective operation |
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| disconnect inverter | of sequence. | voltmeter | |
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| test to make sure of |
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| protective circuit |
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| no fault in protective |
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| output terminals. |
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| and display circuits. |
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| (1) Check for unusual | { |
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| (1) Turn by hand with | (1) Smooth |
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| Cooling fan | vibration and noise. |
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| power off. | rotation. |
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| (2) Check for loose |
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| (2) | (2) No fault. |
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Cooling |
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| connection. |
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system |
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Cooling fan | Is the power supply's |
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| power |
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| Measure with a tester. | 24V±2.4V | Tester | ||
| output voltage correct? |
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| supply |
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| (1) Check if LED lamp | { |
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| (1) Light indicator | (1) Check that |
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| Display | is blown. |
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| lamps on panel. | lamps are lit. |
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| (2) Clean. |
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| (2) Clean with rag. |
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Display |
| Check that reading is | { |
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| Check reading of | Must satisfy |
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| Meter | normal. |
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| meters on panel. | specified and | Voltmeter, | |
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| management | ammeter, etc. | ||
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| values. |
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| (1) Check for unusual | { |
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| (1) Auditory, sensory, | (1), (2) No fault. |
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| vibration and noise. |
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| visual checks. |
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| General | (2) Check for unusual | { |
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| (2) Check for unusual |
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| odor. |
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| odor due to |
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Motor |
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| overheating, |
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| damage, etc. |
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| (1) Check with megger |
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| { | (1) Disconnect cables | (1) 5M Ω or more |
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| Insulation | (across terminals |
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| from U, V, W, |
| 500V megger | |
| resistance | and ground |
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| including motor |
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| terminal). |
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| cables. |
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