Periodic Inspections
Step-type voltage regulators are designed to provide many
years of trouble-free operation. The usable life of a regulator
is affected by its application and periodic inspections are
recommended. The schedule for this will vary, based on
a specific user’s past experience. The Duty Cycle Monitor
feature can assist in determining proper maintenance
intervals. Additionally, the PMT Preventive Maintenance
Tapping feature can automatically perform maintenance
tapping. Refer to
Service Information S225-11-1 Voltage
Regulators, CL-6 Series Control Installation, Operation,
and Maintenance Instructions
for more information on the
Duty Cycle Monitor and PMT features.
Proper operation of the regulator can be checked without
removing the unit from service. Using the manual mode of
operation, run the regulator several steps in the raise direc-
tion and then switch the control back to auto. After the time
delay (set in Function Code 3) expires, the regulator should
return to band edge. When this has been completed, use
the manual mode of operation to run the regulator several
steps in the lower direction and then switch the control
back to auto. After the time delay, the regulator should
return to band edge.
If the regulator will not operate properly, a substitute control
can be tried before removing the unit from service. Refer
to
Service Information S225-11-1 Voltage Regulators, CL-
6 Series Control Installation, Operation, and Maintenance
Instructions
for proper procedures on removing and
replacing the control.
23
S225-10-30
!
SAFETY
FOR LIFE
MAINTENANCE
New
Used
Dielectric Strength (kV)
ASTM D1816
2 mm gap
≥ 45
≥ 40
1 mm gap
≥ 25
≥ 23
Interfacial Tension (mNm)
ASTM D971
≥ 38
≥ 25
Water (mg/kg)
ASTM D1533
≥ 20
≥ 15% **
TAbLE 6
Mineral Oil Characteristics (Type II*)
* Per IEEE C57.106
** 15% relative saturation at operating temperature (Table 3
and Table 5 of IEEE Standard C57.106-2002™)
New
Used
Dielectric Strength (kV)
ASTM D1816
2 mm gap
≥ 45
≥ 40
1 mm gap
≥ 25
≥ 23
Interfacial Tension
ASTM D971-91
(mNm)
—
—
Water
ASTM D1533-88
(ppm maximum)
≥ 100
≥ 400
TAbLE 5
FR3 Fluid Characteristics (natural ester*)
*Per IEEE C57.147 (D11)
