Motor Start Capacitors MS / MD Motor Starting Capacitors MS/MD Series A range of aluminium electrolytic capacitors specifically designs for a.c. operation which help to start the motor by providing a leading current to the auxillary winding. The capacitor is not permanently connected to the winding of the motor and is switched off after starting, usually automatically. Capacitors for this application are designed for intermittent duty only, and must be capable of withstanding the a.c. voltage applied to the motor during starting. This range of capacitors is housed in a moulded case and carry approvals to VDE 560-8 and comply with the requirements of BS 5267 and IEC 252. The MS series is rated at a single voltage whereas the MD has a dual voltage rating. APPROVAL CERTIFICATE DETAILS Voltage MS 120 220 260 MD 220/280 260/330 VDE Approval No. MS and MD 89732 79124 79125 Capacitance range ........... See Motor Start Approval Status Table Capacitance tolerance ...... 10% or -0 to +25% Rated voltage ................ MS - 120, 220 and 260V a.c. MD - 120/150, 220/280 and 260/330 V a.c. Surge voltage ................ 1.25 x rated voltage Climatic category ............ 20/60/21 Temperature range ........... -20C to +60C MS 20/70/21 -20C to +70C MD BHC Components Ltd. 20-21 Cumberland Drive, Granby Industrial Estate, Weymouth, Dorset, DT4 9TE. United Kingdom Tel: +44 1305 782871 Fax: +44 1305 760670 Website: http://www.bhc.co.uk Email:bhcsales@bhc.co.uk MS / MD Motor Starting Capacitors DIMENSIONS mm D2 D1 L(max) Case Code D1 0.5 (mm) AA 38 AB 38 AC 38 D2 0.5 (mm) 39 39 39 Lmax (mm) 75 90 116 ACCESSORIES The following accessories are also available, Leads, Discharge resistors, End Caps, Clamps. BHC Components Ltd. 20-21 Cumberland Drive, Granby Industrial Estate, Weymouth, Dorset, DT4 9TE. United Kingdom Tel: +44 1305 782871 Fax: +44 1305 760670 Website: http://www.bhc.co.uk Email:bhcsales@bhc.co.uk MS / MD Motor Starting Capacitors TECHNICAL DATA Capacitance Motor start capacitors are tested as recommended in BS5267 - `Capacitance shall be determined by measuring the current through the capacitor at the rated voltage and frequency of the capacitor:' The current should be read within 3 seconds after energising.' Capacitance F at 50Hz = 3180 x I V Where: I=current in amperes and V=applied voltage in volts Voltage Rating (a.c.) Due to the presence of the auxiliary start winding, the voltage appearing on the motor start capacitor is usually higher than that of the motor or line voltage. The voltage generally rises with the speed of the motor and varies with the motor load during start-up. Unloaded conditions can give voltages of 15% more than that of loaded. It is essential that the capacitor is disconnected before the voltage exceeds its maximum voltage rating. Rated Voltage (rms) 120 220 260 280 330 Maximum CutOff Voltage (rms) 150 275 325 350 413 Dual Voltage Rating The MD range of BHC Components capacitors is designed with a dual voltage rating. The lower voltage rating relates to a duty cycle of 1.67% and the upper voltage rating relates to a duty cycle of 0.55%. Power Factor The tangent of the loss angle for motor start capacitors shall not exceed 0.1 and shall be calculated as follows: Tan = W = true watts V x I apparent watts BHC Components Ltd. 20-21 Cumberland Drive, Granby Industrial Estate, Weymouth, Dorset, DT4 9TE. United Kingdom Tel: +44 1305 782871 Fax: +44 1305 760670 Website: http://www.bhc.co.uk Email:bhcsales@bhc.co.uk MS / MD Motor Starting Capacitors Duty Cycle The standard rating is 1.67% or 1/60th full time and corresponds to a maximum duty of 20 starts, each of three seconds duration per hour. It is expressed following BS5267: 1967 and IEC 252 1975, as 3/1.67 (a 3 minute cycle with 1.67% duration during which the capacitor may be energised). If the same capacitor is to be used for a duty cycle of 60 starts per hour the cycle duration will be 1 minute. The operation time per cycle will then have to be reduced to 1.67% of 1 minute (i.e. 1 second). Alternative duty cycles are available on request. Most popular are 0.55% and 1%. Presence of a Run Capacitor When the motor is fitted with both starting and run capacitors, consideration should be given to fitting of the appropriate discharge resistor to the starting capacitor. This is to protect the run capacitor from damage through discharge of the starting capacitor. Container Form Cylindrical mouldings, meeting creepage and clearance distances, according to IEC 335-1 and flammability ratings according to UL94-V1. Discharge Resistors A discharge resistor may be fitted to a motor start capacitor to prevent electrical overstress of the capacitor and or for safety reasons. In accordance with BS5267 and IEC252, the resistor value should be such that it reduces the voltage on the capacitor, from the line voltage to less than 50V within 60 secs. The resistor value may be approximated as follows: R (k) max. = T Rated capacitance F Rated Voltage (dc) 120 220 260 280 330 T 50000 32000 30000 28000 26000 Standard Resistor Values Value (Ohms) 5.6K 15K 33K 56K 82K 100K Wattage 2W 2W 0.5W 1W 2W 1W BHC Components Ltd. 20-21 Cumberland Drive, Granby Industrial Estate, Weymouth, Dorset, DT4 9TE. United Kingdom Tel: +44 1305 782871 Fax: +44 1305 760670 Website: http://www.bhc.co.uk Email:bhcsales@bhc.co.uk MS / MD Motor Starting Capacitors Shelf Life Capacitors may be stored for periods up to 2 years without detriment, but after long periods it is a safeguard to test them before putting them into service. In service, the oxide film, which is the dielectric of the capacitor, is maintained in good condition because any imperfections permit a current to pass and the resulting electrolysis forms a new oxide layer. Deterioration of the film takes place if the capacitor is stored for long periods and it is preferable for the `reforming' of the film to be brought about before the capacitor is subject to its full duty. If a motor start capacitor is already connected to the motor, the reforming can be achieved by freeing the motor from its load and switching on several times. Part Numbering: 080 MS 22 AB M A 1 STD MS Series MD Seris Capacitance 080=80F Variants STD = standard design, all other codes used to identify customer and / or special requirements Type MS = Motor start single rating MD = Motor start dual rating Terminal Code 1 = Double amp tag 2 = Special variant Voltage 22 = 220V RMS (rated) Capacitance Tolerance A = -0% +25%, K = 10% Case Size (code) Manufacturing Style M = Moulded case Capacitor Marking The capacitors are marked with all the items from the following list as a minimum. 1. 2. 3. 4. 5. 6. 7. 8. 9. Rated capacitance in F Rated voltage a.c. Duty cycle Frequency Temperature range Date code BHC Components part number Climatic category Approvals BHC Components Ltd. 20-21 Cumberland Drive, Granby Industrial Estate, Weymouth, Dorset, DT4 9TE. United Kingdom Tel: +44 1305 782871 Fax: +44 1305 760670 Website: http://www.bhc.co.uk Email:bhcsales@bhc.co.uk MS / MD Motor Starting Capacitors Capacitance Ranges Series MIN CAP 120V MS12AAMA1STD MS12AAMK1STD MS12ABMA1STD MS12ABMK1STD MS12ACMA1STD MS12ACMK1STD MD12AAMA1STD MD12AAMK1STD MD12ABMA1STD MD12ABMK1STD MD12ACMA1STD MD12ACMK1STD Series MAX CAP (F) (F) 25 25 85 90 120 130 25 25 85 90 120 130 MIN CAP 220V MS22AAMA1STD MS22AAMK1STD MS22ABMA1STD MS22ABMK1STD MS22ACMA1STD MS22ACMK1STD MD22AAMA1STD MD22AAMK1STD MD22ABMA1STD MD22ABMK1STD MD22ACMA1STD MD22ACMK1STD Series 325 360 460 510 670 750 325 360 460 510 670 750 MAX CAP (F) -0% +25% 10% -0% +25% 10% -0% +25% 10% -0% +25% 10% -0% +25% 10% -0% +25% 10% 65 70 90 100 130 150 65 70 90 100 130 150 MAX CAP (F) -0% +25% 10% -0% +25% 10% -0% +25% 10% -0% +25% 10% -0% +25% 10% -0% +25% 10% (mm) 38x75 38x75 38x90 38x90 38x116 38x116 38x75 38x75 38x90 38x90 38x116 38x116 Tolerance Can Size (F) 25 25 35 35 50 55 25 25 30 35 45 50 (mm) 38x75 38x75 38x90 38x90 38x116 38x116 38x75 38x75 38x90 38x90 38x116 38x116 Duty Cycle @ 120V rms Voltage=150V) 55 60 75 85 110 125 50 55 70 80 100 115 -0% +25% 10% -0% +25% 10% -0% +25% 10% -0% +25% 10% -0% +25% 10% -0% +25% 10% (mm) 38x75 38x75 38x90 38x90 38x116 38x116 38x75 38x75 38x90 38x90 38x116 38x116 (Surge @ 150V rms (Surge Voltage=188V) 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% Tolerance Can Size (F) 30 30 40 40 55 65 30 30 40 40 55 65 MIN CAP 260V MS26AAMA1STD MS26AAMK1STD MS26ABMA1STD MS26ABMK1STD MS26ACMA1STD MS26ACMK1STD MD26AAMA1STD MD26AAMK1STD MD26ABMA1STD MD26ABMK1STD MD26ACMA1STD MD26ACMK1STD Tolerance Can Size 0.55% 0.55% 0.55% 0.55% 0.55% 0.55% Duty Cycle @ 220V rms Voltage=275V) (Surge @ 280V rms (Surge Voltage=350V) 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 0.55% 0.55% 0.55% 0.55% 0.55% 0.55% Duty Cycle @ 260V rms (Surge Voltage=325V) @ 330V rms (Surge Voltage=413V) 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% 1.67% BHC Components Ltd. 20-21 Cumberland Drive, Granby Industrial Estate, Weymouth, Dorset, DT4 9TE. United Kingdom Tel: +44 1305 782871 Fax: +44 1305 760670 Website: http://www.bhc.co.uk Email:bhcsales@bhc.co.uk 0.55% 0.55% 0.55% 0.55% 0.55% 0.55% MS / MD Motor Starting Capacitors Approval Status RATED VOLTAGEO APPROVALO CAPACITOR TYPEO CAPACITANCE (uF) 25 30 35 40 50 60 70 80 90 100 120 125 150 160 180 200 230 250 300 310 315 350 400 120 VDE MS AA AA AA AA AA AA AA AA AA AA AA AA AB AB AB AB AB AC AC AC AC 220V VDE MS 260V VDE MD VDE MS AC AA AA AA AA,AB AA,AB AA,AB AB,AC AB,AC AB,AC AB,AC AC AC AA AA,AB AA,AB AA,AB AB AB AB AB AB AB AB The table above shows the capacitor values that have been approved within the can sizes shown. Other unapproved capacitor values are available upon request. BHC Components Ltd. 20-21 Cumberland Drive, Granby Industrial Estate, Weymouth, Dorset, DT4 9TE. United Kingdom Tel: +44 1305 782871 Fax: +44 1305 760670 Website: http://www.bhc.co.uk Email:bhcsales@bhc.co.uk VDE MD AB AB AB AB AB Iss1: 01\08\02