PMW Range

Specifications

They are impregnated and filled with a mineral oil. The container is manufactured from heavy gauge, cold rolled steel that is welded and hermetically sealed. The internal construction is designed to prevent movement when subjected to vibration or mechanical shock. The capacitors’ containers are primed and glossed. The capacitors may be supplied with fixing brackets, handles or lugs for lifting. Larger capacitors are mounted on wheels.

NOTE: The impregnant used is a non toxic highly refined, purified and inhibited mineral oil.

APPLICATIONS: The PMW range of capacitors are specially designed for DC filtering and bypass applications such as high voltage power supplies for lasers, radar and x-ray, RF transmitters, traction equipment and generators where reliability and long life are prime considerations.

Capacitance Range: 0.01µF-100µF. The tolerance is +/-10%. Other tolerances are available on request. Nominal values measured at 1kHz.

Temperature Range: -55°C to 85°C. The nominal voltage rating is applicable from -55°C to 85°C. Derating is required for higher operating temperatures.

Temperature Coefficient: Capacitance will increase by 2% per 100ºC temperature change.

Voltage Range: 1KVDC - 80kVDC

RIPPLE:

Ripple: The sum of the peak ripple voltage and the DC voltage should not exceed the rated voltage. The graph above shows permissible peak-to-peak ripple voltage as a percentage of rated voltage for various frequencies.

Test Voltage: V Test	(Terminal to (Terminal)
For DCrating <20kV	Vtest=2.0 x Rated Voltage for 1 miute
For DC rating >20kV	Vtest=1.5x Rated Voltage for 1 minute
Case to terminal Test voltage	VTest+1kV (Note where necessary terminals are joined together during testing)

Test Voltage: V Test
For DC rating <20kV:		V Test = 2.0 x Rated Voltage for 1 minute.
For DC rating ≥20kV:		V Test = 1.5 x Rated Voltage for 1 minute.
Case to terminal Test voltage = V Test + 1kV

Power Factor

Power Factor: Variable; function of temperature and frequency. See fig 2. Nominal value < 0.5% at 20ºC.

Dieletric Resistance

Dieletric Resistance: (Parallel resistance) Indicated by the graph of insulance (Mohms x µF) vs Temperature (fig 3). The insulance(Mohms x µF) is nominally 10000s at +20ºC. (Measurements taken after 1 minute with an applied voltage of 500V).

Life expectancy

Life expectancy: PMW type capacitors are designed for a life expectancy of 50000 hours at 65ºC. To achieve the same life expectancy at 85ºC derate to 60% of rated voltage.

Flashover

V Rated < 5kV, the terminals will withstand 125% of rated voltage without flashover @ 85mm Hg (equivalent to 50000 ft altitude).

V Rated > 5kV, the terminals will withstand 125% of rated voltage without flashover @ 500mm Hg (equivalent to 10000 ft altitude).

Dimensions

SELECT WORKING VOLTAGE:

PMW Dimensions

Kilovolts	Capacitance	A	B	C
DC	µF
6	24	345	160	130
6	40	450	250	145
7.5	35	260	250	170
8	37	530	290	150
8	9	200	305	120
10	32	380	325	205
10	5	200	160	140
10	8	260	250	105
12	4	270	215	180
15	7	380	290	125
15	12	710	355	130
15	35	660	455	230
18	4	380	330	105
18	7	380	325	165
20	4	380	340	120
20	7	710	355	130
20	10	695	470	100
20	20	695	470	180
25	2	380	330	105
25	4	540	305	125
25	5	530	350	140
25	12	720	570	200
30	1	260	255	160
30	2	370	330	130
30	4	540	385	135
40	4	400	600	235
60	2	570	415	270
80	0.1	235	310	130

NOTES:

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