SNP Type Non Polar & SP Type


These capacitors are known for its high performance and reliability.

SALIENT FEATURES

  • Designed for withstanding internal vibration stresses.
  • Provided with phenol molded bakelite disc with screwed terminals.
  • Non Polar Type, where the polarity is unknown.
  • Highly insulated with a safety vent valve.
  • Low Impedance & Inductance are achieved by special construction with multiple anode & cathode.

APPLICATIONS

  • Diesel/Electric locomotive applications
  • Military equipments
  • DC welding machines
  • Thyristor control equipments

TECHNICAL FEATURES

Operating Temperature Range

-40°C To +85°C

Rated Voltage Range

12 V To 450 VDC

Capacitance Range & Tolerance at 100Hz & 25°C

Range:10 Mfd To 2000 Mfd
Tolerance:    -10% To +30%

Leakage Current (µA Max)

(Apply rated voltage for 5 minutes before test)

I= 0.01 CV or 4mA whichever is less

I= Leakage Current (µA)

IC= Rated Capacitance (Mfd)

V= Rated Voltage (V)

Dissipation Factor
(% Max at 100Hz & 25°C)

Rated Voltage

50V

100-200V

250-450V

Tan d

18

16

10

For Capacitance whose Capacitance value exceed 1000Mfd, Tanð is increased by 2% for every addition of 1000Mfd.

Life Test at 85°C & at Rated Voltage

Test Hours-2000 Hours
Capacitance change-within ± 20% of the initial value
Tanð/Dissipation Factor- Less Than 120% of column 6
Leakage Current-Less Than the value given in column 5

Other Tests

As per IS-4317-1983 (Category)2A


STANDARD CAPACITANCE TABLE WITH CORRESPONDING GE CATALOGUE & RAILWAY PL NUMBER:

SL. NO.

SARADA Type No.

Cap. in MFD

Working Voltage

Type

Size DxL in mm

Railway PL No.

GE Catalogue number

1

S 204 PAN

2000

50

Polar

46x111

12395341

598x95

2

S 134 PBN

1300

100

Polar

52x111

12395304

482A342P1

3

S 154 PBN

1500

100

Polar

52x111

12395304

482A342P1

4

S 503 NPAN

500

125

Non-Polar

46x111

12395043

41A250094P1

5

S 503 NPBN

500

125

Non-Polar

52x111

-

-

6

S 104 PAN

1000

150

Polar

46X111

12395067

41A250094P13

7

S 103 NPAN

100

250

Non-Polar

46X111

12395080

41A250094P9

8

S 302 NPCU

30

300

Non-Polar

36X72

12395547

41A250094P6

9

S 502 NPCU

50

300

Non-Polar

36X72

12395055

41A250094P11

NOTE:

  • Other sizes/ values are available on request
  • The technical specifications and availability of the products specified in this catalogue are subject to change due to availability of better raw materials & improved design.

PRECAUTIONS TO BE TAKEN WHEN USING ALUMINUM ELECTROLYTIC CAPACITORS:

If the capacitors are used beyond the specified limits short circuiting, opening, solution leakage, explosion, ignition or other fatal failure may occur. Detailed information about the precautions to be taken is given below:

I. CAPACITORS FOR DC APPLICATION REQUIRE POLARISATION:
Ensure correct polarity (polarity is clearly indicated on the capacitors). If used with reverse polarity, the circuit life may be shortened or the capacitors may be damaged and may further result in explosion, if the unit is energized for a long time. "SARADA" offers capacitors with safety vent design as standard type in order to prevent possible accidents. It is recommended to use non polar capacitors for DC circuits where the polarity may be reverse or unknown.

II. WHILE USING CAPACITOR AFTER PROLONGED STORAGE:
When electrolytic capacitors are stored for a long time without use, its withstand voltage is liable to drop resulting in increased leakage current and may cause electric breakdown due to thinness of the oxide film and heat generated from excessive leakage current. It is recommended that the capacitors be preconditioned as given below:

PRECONDITIONING: Capacitance of our capacitors is always on the higher capacitance. It is advised that before starting the test sequence, the capacitors be preconditioned by applying the rated working voltage across the capacitors. The power supply must be regulated DC power and suitable current limiting resistor must be connected in series. The value of it shall be approximately 100 Ohms for rated voltage up to 100 volts and approximately 1000 Ohms for rated voltage more than 100 volts. The voltage shall be maintained for an hour after its value across the capacitor has been equal to the rated voltage. The capacitor may be stored idle for 24 hours. After this period, the capacitor may be tested for any one of the parameter specified.

III. APPLIED VOLTAGE:

1) If the applied voltage exceeds the rate working voltage, the leakage current increases and the capacitor may be damaged. The sum of the AC peak & DC voltage shall not exceed the value of the rated voltage.

2) When connecting a number of capacitors in series, use capacitors having the same rating. Connect balancing resistors in parallel. Here, we have to consider wiring resistance into account otherwise; the voltage applied to the capacitors may vary resulting in capacitor deterioration.

IV. OPERATING TEMPERATURE & RIPPLE CURRENT:

1) Use the capacitors within the specified temperature. If the temperature shoots up, it is hazardous to capacitors and its performance deteriorates.

2) Excessive ripple may cause excessive heat inside the capacitors and the capacitor may damage.

3) When connecting two or more capacitors in parallel take the wiring resistance into account. For this make wiring connections so that all capacitors are subjected to the same wiring resistance.

V. SCREW TERMINALS:
The terminal section tightening torque should be 2.5 Nm (max). Do not apply excessive force on the screw. Advisable maximum connector thickness with delivered screws: 4 mm.

VI. MOUNTING:
Ensure that screw terminals type safety vents do not face downwards. Because electrolytic solution may flow out of the safety vent. When numbers of capacitors are connected in a bank, a minimum distance of 15 mm may be kept between the capacitors for better thermal dissipation.

VII. INSULATION & GROUNDING:
Capacitors with insulated cases should have the case grounded or protected. Electrolytic capacitors exhibit an indeterminant resistance between cathode terminal and the metal case.The metal case should therefore be considered at the same potential as the cathode terminal with respect respect to the ground. Where a potential difference exists between the cathode terminal and chassis or any other metallic mounting surface which are usually ground, the capacitor should be mounted in such a manner as to insulate the metal case from such mounting surface.

VIII. SOLDERING FOR TERMINAL TYPE CAPCITORS:
The characteristics of the capacitors will be adversely affected if they are dipped in solder too long or if the solder temperature is too high. Capacitor shall be dipped in solder of 260°C or below for 10 seconds or less.

IX. CLEANING AGENTS FOR CIRCUIT BOARD:
Aluminum electrolytic capacitors that have been exposed to halogenated hydrocarbon cleaning and de-fluxing solvents are susceptible to attack by solvents. This exposure may lead to solvent penetration into the capacitors causing internal corrosion and potential failure. Therefore alcohol system may be used for cleaning circuit boards. It is advisable to use Isopropyl Alcohol, Methanol, etc.

X. MAINTENANCE:

  1. Capacitors used in industrial equipment must be inspected on a periodic basis.
    The inspection items are as follows:
    • Appearance (e.g. safety vent condition)
    • Electrical parameters (e.g. capacitance, dissipation factor and leakage current)
  2. If the capacitors have reached the end of their useful life, they must be replaced. If any capacitor in equipment needs to be replaced, replace all capacitors used in the same equipment. If new and old ones are together an unbalanced ripple current or voltage sharing can result.

XI. WARNING:
Electrolytic capacitors may contain chemicals, which may be regarded as hazardous, if incorrectly handled and hence caution is necessary.

XII. STORAGE:
Better always store aluminum electrolytic capacitors in low humid atmosphere and at low temperature.