Siemens 38-3AH3 38 kV instruction manual Circuit Number, Inspection of primary disconnects

Maintenance

Figure 38: Primary disconnect in mated position

Circuit	Number of
breaker type	years/closing
	operations
	(whichever
	comes first)
38-3AH3	10 years/
	10,000
	operations

Table 2: Maintenance and lubrication schedule

Inspection of primary disconnects

Figure 38: Primary disconnect in mated position shows the primary-disconnect contact-fingers engaged. When the contacts are mated with the switchgear primary-stud assembly, there is forceful contact distributed over a wide area. This maintains low-current flow per individual contact finger.

Inspect the contact fingers for any evidence of burning or pitting that would indicate weakness of the contact-finger springs.

Inspect the primary-disconnect arms for physical integrity and absence of mechanical damage.

Inspect the flexible connectors that connect the bottom movable-contacts of the vacuum interrupters to the lower primary-disconnect arms for tightness and absence of mechanical damage, burning or pitting.

Using a clean cloth saturated with isopropyl alcohol, clean old lubricant from primary disconnects, and apply a very thin layer of Siemens contact lubricant (reference 15-172-791-233).

Checks of the stored-energy operator mechanism

The stored-energy operator checks are divided into mechanical and electrical checks for simplicity and better organization. This first series of checks determine if the basic mechanism is clean, lubricated and operates smoothly without control power. The contact-erosion check of the vacuum interrupter is also performed during these tasks.

Maintenance and lubrication

Table 2 gives the recommended maintenance intervals for circuit breakers. These intervals assume the circuit breaker is operated under “usual service conditions” as discussed in ANSI/IEEE C37.20.2, section 8.1, and C37.04, section 4, together with C37.010, section 4. The maintenance and lubrication interval is the lesser of the number of closing operations or the time interval since last maintenance.

The vacuum-interrupter operator mechanism is shown in Figure 39: Operator mechanism lubrication on page 45, with the front cover and the operator- control panel removed to show construction details.

Both the tripping spring and the closing spring are shown. The movable end of the closing spring is connected to a crank arm. The movable end of the opening spring is connected to the jack shaft by a pull rod.

Clean the entire stored-energy operator mechanism with a dry, lint-free cloth.

Check all components for evidence of excessive wear.

Place special attention on the closing spring-crank and the various pushrods and linkages.

Lubricate all non-electrical moving or sliding surfaces with a light coat of synthetic grease or oil.

Lubricants composed of ester oils and lithium thickeners will generally be compatible.

For all lubrication (except electrical moving or sliding surfaces), use one of the following:

Klüber Isoflex Topas L32 (part 3AX11333H)

Klüber Isoflex Topas L32N (spray) (part 15-172-879-201).

Source:

Klüber Isoflex Topas L32 or L32N: Klüber Lubrication North America L.P. www.klueber.com

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