page_197

< previous page | page_197 | next page >

Page 197

TABLE 10-1 Troubleshooting Disconnecting Devices

Condition

Possible Cause

Suggested Remedy

| Discoloration, signs of over-heating |

Overload

Replace with proper rated unit.

Contacts poor

| Check and dress contacts; resilver line contacts if necessary. Check alignment of contacts and operation of closing mechanism. |

Loose connection

| Check and tighten all connections, clamps, etc. |

| In an oil switch, dirty oil or low oil level |

| Check oil, filter it, and refill tank to proper level. Clean all parts inside tank with clean oil. |

Noisy switch

| Loose bolts, pitting, linkages, etc. |

| Tighten all parts, bolts, links, etc., and replace if necessary. |

| Sluggish and uneven closing of gang switches |

| Loose linkages in control devices |

| Check alignment and tightness of linkages and the condition of bolts, cotter pins, guide plates, etc. Tighten or replace if necessary. |

| Cracked or chipped insulators |

| Flashover from dirt or contamination; lightning |

| Clean insulators, replace with larger insulators if necessary. Check grounds and lightning arrester installation. |

| Operating handles energized |

| Leakage from dirty insulators; poor grounds or ground connections |

| Clean insulators or replace as above. Check ground resistance and install additional grounds if necessary. Tighten all ground connections. Bond to other structures if practical. |

Oil leakage (oil switches)

| Leaks; improper oil level; oil thrown during transient short circuit |

| Check and repair leaks. Fill tank to proper level. Check internal parts for damage Replace with larger unit if necessary. |

| Rust and paint deterioration |

| Weather; polluted or salt atmosphere; overloads |

| Remove rust and deteriorated paint. Clean surfaces. Repaint with proper paint and sufficient coatings. |

| which, under some conditions, can safely interrupt relatively small currents. Switches, however, are almost always operated in series with circuit breakers or fuses. |

| 4. Switches are generally used to insert a physical separation in a circuit associated with circuits or equipment as a safety measure to ensure the |

< previous page | page_197 | next page >