Aluminum Electrolytic Capacitor
(5)Clearance for Case Mounted Pressure Relief Vents
Capacitors with case mounted pressure relief vents require sufficient clearance to allow for proper vent operation. The minimum clearances are dependent on capacitor diameters as follows.
f6.3 to f16 mm | : 2 mm minimum, |
f18 to f35 mm | : 3 mm minimum. |
f40 mm or greater: 5 mm minimum
(6)Clearance for Seal Mounted Pressure Relief Vents
A hole in the circuit board directly under the seal vent location is required to allow proper release of pressure.
(7)Wiring Near the Pressure Relief Vent
Avoid locating high voltage or high current wiring or circuit board paths above the pressure relief vent. Flammable, high temperature gas exceeding 100°C may be released which could dissolve the wire insulation and ignite.
(8)Circuit Board Patterns Under the Capacitor
Avoid circuit board runs under the capacitor as electrolyte leakage could cause an electrical short.
(9)Screw Terminal Capacitor Mounting
●Do not orient the capacitor with the screw terminal side of the capacitor facing downwards.
●Tighten the terminal and mounting bracket screws
w i t h i n t h e t o r q u e r a n g e s p e c i f i e d i n t h e specification.
1.6Electrical Isolation of the Capacitor
Completely isolate the capacitor as follows.
●Between the cathode and the case (except for axially leaded B types) and between the anode terminal and other circuit paths.
●Between the extra mounting terminals (on T types) and the anode terminal, cathode terminal, and other circuit paths.
1.7 Capacitor Sleeve
The vinyl sleeve or laminate coating is intended for marking and identification purposes and is not meant to electrically insulate the capacitor.
The sleeving may split or crack if immersed into solvents such as toluene or xylene, and then exposed to high temperatures.
Always consider safety when designing equipment and circuits. Plan for worst case failure modes such as short circuits and open circuits which could occur during use.
(1)Provide protection circuits and protection devices to allow safe failure modes.
(2)Design redundant or secondary circuits where possible to assure continued operation in case of main circuit failure.
2.Capacitor Handling Techniques
2.1 Considerations Before Using
(1)Capacitors have a finite life. Do not reuse or recycle capacitors from used equipment.
(2)Transient recovery voltage may be generated in the capacitor due to dielectric absorption. If
required, this voltage can be discharged with a resistor with a value of about 1 kΩ.
(3)Capacitors stored for long periods of time may exhibit an increase in leakage current. This can
be corrected by gradually applying rated voltage in series with a resistor of approximately 1 kΩ.
(4)If capacitors are dropped, they can be damaged mechanically or electrically. Avoid using dropped capacitors.
(5)Dented or crushed capacitors should not be used. The seal integrity can be compromised and loss of electrolyte/shortened life can result.
2.2 Capacitor Insertion
(1)Verify the correct capacitance and rated voltage of the capacitor.
(2)Verify the correct polarity of the capacitor before inserting.
(3)Verify the correct hole spacing before insertion (land pattern size on chip type) to avoid stress on the terminals.
(4)Ensure that the auto insertion equipment lead clinching operation does not stress the capacitor leads where they enter the seal of the capacitor. For chip type capacitors, excessive mounting pressure can cause high leakage current, short circuit, or disconnection.
2.3 Manual Soldering
(1) O b s e r v e t e m p e r a t u r e a n d t i m e s o l d e r i n g specifications or do not exceed temperatures of 350°C for 3 seconds or less.
(2)If lead wires must be formed to meet terminal board hole spacing, avoid stress on the leadwire where it enters the capacitor seal.
(3)If a soldered capacitor must be removed and reinserted, avoid excessive stress to the capacitor leads.
(4)Aviod touching the tip of the soldering iron to the capacitor, to prevent melting of the vinyl sleeve.
Design, Specifications are subject to change without notice. Ask factory for technical specifications before purchase and/or use.
Whenever a doubt about safety arises from this product, please inform us immediately for technical consulation without fail.
– EE19 –
Mar. 2005