Siemens 21-115532-001 ユーザーズマニュアル

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M A I N T E N A N C E  
Page 12 
PERIODIC INSPECTION 
A sample of oil from the regulator should be subjected to 
dielectric breakdown test, per ASTM D-877. If found below 
25kV, the oil should be changed or reconditioned.  Refer to 
ANSI C57.106-2002.   Other tests, especially Neutralization 
Number, Interfacial Tension and Power Factor are also useful 
and may be preferred by particular users. 
The oxidation inhibitor in the oil will be depleted over a period 
of a few years and should be replaced. The inhibitor is 2, 6-
ditertiary-butyl-para-cresol (DBPC) at a concentration level of 
0.2 to 0.3%. 
The time interval between internal inspections will depend 
upon frequency of tapchanger operation and the load on the 
regulator. Regulators subjected to numerous overloads and a 
high load factor may require more frequent inspections than 
those carrying normal loads. While internal inspection is not a 
necessity, preventive maintenance inspections will help assure 
the continuity of service. 
To untank a JFR regulator, proceed as folllows: 
1.  Remove the regulator from service as described on 
Page10.
 
 
 
2.  Place the regulator in a position where energized 
overhead lines will not interfere. 
3.  Operate pressure relief valve to vent regulator before un-
tanking 
4.  Remove the mounting bolts holding the control box onto 
the main tank. 
5.  Remove all cover bolts. 
6.  The regulator can now be pulled from the main tank by the 
cover lifting eyes. 
 
 
When inspecting, check to be certain all hardware and con-
nections are tight. The principal point of the internal inspection will 
be the condition of the arcing contacts on the tapchanger. Since 
numerous factors influence the rate of contact tip wear, no one 
criteria can be stated to recommend when a contact should be 
changed. 
 
The following figure shows the possible condition of contact wear 
after a period of operation. If the contact surface is less than 1/8 
inch wide, the contact should be replaced. (See the Figure below) 
 
Contacts, both movable and stationary, show normal burning and wear 
once placed in service. If for any reason A1 dimensions exceed 4/5 of 
A, the stationary contact should be replaced. (See the Figure below) 
 
• 
UPPER FILTER PRESS SEALING 
 
If cover top cap is removed, make certain the cap is properly 
sealed when replaced on cover. Siemens recommends applying 
pipe sealant (Loctite PST or equivalent) around the threads of the 
adapter. Furthermore, it is recommended that the seal be tested by 
applying 5 psig pressure through the pressure relief valve fitting for 
5 minutes, with no loss in pressure. Failure to assure seal may 
allow moisture to be pulled into the unit during a cool-down cycle.
 
 
• 
FAN MAINTENANCE 
 
Cooling fans (if equipped), require  minimum attention. Fans with 
plain sleeve bearings or 
Oil-Lite 
sleeve bearings should be oiled at 
least once a year with  SAE 10-W engine oil which does not thicken 
in cold weather. Oil must be added to sleeve bearings before 
starting motor for the first time after installation.
 
 
Fans equipped with ball bearing motors are packed with grease 
before shipment and should be greased at least once a year with a 
soda-soap, ball-bearing grease of medium consistency furnished 
by a reliable supplier. 
 
A
A1
 
Hazardous voltages. Will cause serious injury, death, or 
equipment damage.  
 
To prevent: 
 
Always de-energize and ground the equipment before 
maintenance requiring access to high voltage parts.