BFM Three Phase HV Shunt Capacitors

Series Part Number

Part Number:	BFM	6.6	-	100	-	3	W
Explanation:	Product and Materials B - Shunt capacitor F - Diaryl ethane (PXE) impregnant M - Full-film solid dielectric	Rated Voltage 6.6 - Rated voltage of 6.6kV; this three-phase schedule also lists 11kV and 12kV units		Reactive Output 100 - Rated reactive output of 100kvar in this model; use an actual voltage/output combination from the selection schedule		Phase Count 3 - Three-phase construction; the family's 1 designation identifies a separate single-phase construction	Installation W - Outdoor construction; the family diagram omits this suffix for indoor construction. The listed models all carry W.

Description

BFM three-phase shunt capacitors supply reactive power for power-factor correction in high-voltage power systems. These full-film units use a steel case and porcelain terminals. The selection schedule covers 15 outdoor models at 6.6kV, 11kV and 12kV, with outputs from 100kvar to 600kvar.

The BFM family is described for 50Hz or 60Hz power systems. The output and capacitance pairs in this schedule correspond to 50Hz; select a unit with the specified frequency and voltage for the actual installation. Each listed three-phase unit follows the three-terminal Fig.2 outline below.

Electrical and Construction Characteristics

Characteristic	BFM family requirement
Dielectric and impregnant	Full-film dielectric; F denotes diaryl ethane (PXE) impregnant
Capacitance tolerance	−5% to +5%
Three-phase capacitance balance	Maximum-to-minimum terminal-pair capacitance ratio ≤1.08
Full-film loss tangent	tanδ ≤0.0005
Terminal-to-terminal withstand	2.15Un AC or 4.3Un DC for 10s, without breakdown or flashover
Terminal-to-case withstand	For terminals insulated from the case, the test follows clause 18.1 of GB/T11024.1-2010
Continuous overcurrent capability	Up to 1.3In from elevated voltage and harmonics; up to 1.37In when the maximum positive capacitance tolerance is included
Switching surge capability	Up to 100In; no more than 1000 surge events in the stated duty, including some events at internal temperatures ≤0°C
Internal discharge resistor	Reduces terminal voltage to ≤75V within 10min after disconnection
Referenced product standard	GB/T11024.1-2010; the family specification also cites the historical IEC871-1 reference

Un and In mean the unit's rated voltage and current. Operation within the rated voltage and current is preferred for service life; permissible overload limits are not continuous design targets. The film-and-paper loss limit quoted for other constructions does not replace the full-film BFM value.

Three-Phase Model Schedule

All dimensional values are in millimetres. L1, L2, L3, B, H1, H2 and A refer to Fig.2. H1 is case height and H2 includes the porcelain terminals. Ceq is the equivalent three-phase capacitance used with rated line voltage, rather than the sum of individual star-connected elements.

No.	Model	Rated voltage (kV)	Output (kvar)	Ceq (µF)	Dimensions (mm)							Outline
No.	Model	Rated voltage (kV)	Output (kvar)	Ceq (µF)	L1	L2	L3	B	H1	H2	A	Outline
1	BFM6.6-100-3W	6.6	100	7.31	500	550	580	110	370	590	200	Fig.2
2	BFM6.6-200-3W	6.6	200	14.62	500	550	580	115	370	590	200	Fig.2
3	BFM6.6-300-3W	6.6	300	21.93	600	650	680	150	370	590	230	Fig.2
4	BFM11-100-3W	11	100	2.63	500	550	580	115	370	590	200	Fig.2
5	BFM11-200-3W	11	200	5.26	600	650	680	150	370	620	250	Fig.2
6	BFM11-300-3W	11	300	7.89	600	650	680	170	450	700	250	Fig.2
7	BFM11-400-3W	11	400	10.53	600	650	680	240	450	700	250	Fig.2
8	BFM11-500-3W	11	500	13.16	600	650	680	240	450	700	250	Fig.2
9	BFM11-600-3W	11	600	15.79	600	650	680	240	450	700	250	Fig.2
10	BFM12-100-3W	12	100	2.21	500	550	580	115	370	590	230	Fig.2
11	BFM12-200-3W	12	200	4.42	600	650	680	150	370	620	250	Fig.2
12	BFM12-300-3W	12	300	6.63	600	650	680	170	450	700	250	Fig.2
13	BFM12-450-3W	12	450	9.95	600	650	680	170	450	700	250	Fig.2
14	BFM12-500-3W	12	500	11.06	600	650	680	240	450	700	250	Fig.2
15	BFM12-600-3W	12	600	13.27	600	650	680	240	450	700	250	Fig.2

BFM high-voltage capacitor case and terminal dimensions — Use Fig.2, the lower three-terminal drawing, for every model in this schedule. Fig.1 shows the separate single-phase construction. A is the adjacent terminal spacing in Fig.2.

Model Identification

In BFM6.6-100-3W, BFM identifies a shunt capacitor with F-type impregnant and full-film dielectric, 6.6 is rated voltage in kV, 100 is output in kvar, 3 denotes three phases and W denotes outdoor construction. The family code diagram omits W for indoor construction; this schedule specifically lists W models.

BFM shunt capacitor identification fields — Common BFM model fields: product and material designation, voltage, output, phase count and outdoor suffix. The alternative A impregnant designation belongs to a different material code.

Permissible Power-Frequency Voltage

Voltage relative to Un	Maximum stated duration	Operating circumstance
1.00	Continuous	Normal service; exceptional higher-voltage periods are limited as below
1.10	12h in each 24h	System voltage regulation and fluctuation
1.15	30min in each 24h	System voltage regulation and fluctuation
1.20	5min	Voltage rise during load changes
1.30	1min	Short exceptional overvoltage; no repeating daily allowance is specified

Installation, Inspection and Capacitance Checks

For ordinary installations, the family guidance limits altitude to 1000m and identifies several ambient-temperature categories: −40/A, −25/A, −5/A and −5/C. Select the category marked for the actual unit. The maintenance guidance also gives an outer ambient envelope of −50°C to +55°C, with a 24h average ≤30°C and an annual average ≤20°C; this does not extend the marked temperature category of any listed unit.

Arrange units for ventilation, with no more than three layers and two rows per layer. The general layout guidance specifies at least 200mm spacing indoors, 300mm outdoors and 1000mm clearance to the roof. Case earthing or insulated support must follow the bank connection and case-insulation arrangement. Preserve the required electrical clearances for the complete installation.

Keep porcelain bushings, cases and supports clean. Inspect busbars, earth conductors, breakers, fuses, switches and all connections for secure contact. At light load, capacitor connection can raise system voltage; disconnect sufficient capacitance if terminal voltage exceeds 1.1Un during routine operation. If protection trips, establish and remove the fault before reclosing. Isolate a leaking or damaged unit for qualified service or replacement.

The internal resistor is a discharge provision; its stated time is not permission to touch terminals. Isolate the bank and verify discharge before inspection or measurement.

For a balanced three-phase unit, measure capacitance between terminal pairs AB, BC and CA with the third terminal open. The equivalent value is Ceq = (2/3) × (Cab + Cbc + Cca), applicable to the equivalent rating convention for either an internal star or delta connection. With line voltage U, the 50Hz schedule follows Q = 2πfU²Ceq. Use consistent SI units when calculating; a terminal-pair reading alone is not the complete three-phase rating.

BFM Three Phase High Voltage Shunt Capacitors