Aerovox Capacitor Specifications
Aerovox capacitors for HID Lighting applications are typically marked "90oC" or "100oC max". Capacitor life is mainly affected by voltage and temperature. They are designed for 60,000 hours continuous duty at rated voltage and average operating temperatures of 90oC. On going Accelerated Life Test programs verify Aerovox capacitor designs and production units. Special designs may be supplied where capacitors operate continuously above 90o. Temperature is defined as the highest reading on any area of capacitor case. Operation over 90oC (212oF) will reduce operating life. Guideline: each 6.5 degree rise over 90oC reduces life by 50%. Aerovox capacitors can be operated at low temperatures (to -40oC without de-rating).
Aerovox capacitors are non-polar (terminals/electrodes can be reversed), unlike many "electrolytic" capacitors which have plus and minus terminals that will cause catastrophic failure when reversed. Along with being non-polar, metallized film capacitors are self-clearing. During momentary faults, small areas of metallized electrodes vaporize and capacitor function is restored (usually with small reductions in micro farads until end of capacitor life).
Aerovox capacitors include: agency listings outlined below), accelerated life testing programs, and protective devices (interrupters). Ongoing testing programs total over 500 million component test hours each year at Aerovox New Bedford. Safety Agency listings are continuously monitored programs. Testing also includes fault-current requirements on interrupter mechanisms per UL#810. Protective devices cause open circuits at end of capacitor life, versus short circuits that can be caused by capacitors without protective devices.
Aerovox capacitors outlined in this catalog utilize two basic types of construction; oil-filled metal cases and dry units (epoxy filled plastic cases). These capacitor designs, materials, and construction are all documented per ISO 9001 and closely controlled. Materials used in Aerovox capacitors are only obtained from certified sources and monitored. Aerovox capacitors cover a wide range of case styles including dual-caps (two capacitors in one case).
Aerovox capacitors use special types of polypropylene film. Polypropylene films are the most energy efficient dielectric materials commercially available for continuous duty AC voltage applications. Capacitor efficiency is measured as % DF (dissipation factor). Aerovox capacitor DF's are typically less than 0.1% at 60Hz and 70oC (158oF). Other types of capacitors typically have much higher DF's. Examples; Aluminum Electrolytic capacitors can have DF's over 10% at 25oC and polyester film DF increases with temperature. Aerovox capacitors are capable of continuous duty with very low Microfarad losses.
Polypropylene plastic films used by Aerovox are specially made to close tolerance thicknesses that are engineered for various AC voltage ratings at 50/60 HZ RMS. These films are metallized, and wound into rolls (two layers with opposing margins). Roll ends are then sprayed with metal to connect layers and form capacitor electrodes at each end. Note: oil-filled capacitors can use thinner dielectrics than comparable dry capacitors.
Aerovox capacitors include: accelerated life testing programs, and protective devices (interrupters). Ongoing testing programs total over 500 million component test hours each year at Aerovox New Bedford. Safety Agency listings are continuously monitored programs. Testing also includes fault-current requirements on interrupter mechanisms per UL#810. Protective devices cause open circuits at end of capacitor life, versus short circuits that can be caused by capacitors without protective devices.
Aerovox metal case capacitors use soybean-oil or Polyisobutylene-oil, to extend design life. These oils protect metalized film from corrosion, aid heat transfer, and help suppress corona (which may otherwise cause premature failures). Aerovox oil-filling processes utilize proprietary cycles of vacuum and heat to remove ambient moisture in cases (which would otherwise reduce operating life of capacitors). Protective devices (interrupters) in oil-filled metal cases: Connections to film rolls are made with tabs welded to each end and connected to case terminals through an interrupter mechanism; interrupter mechanisms cause an open circuit at end of capacitor life.
Dry Plastic Case Capacitors made by Aerovox for HID lighting applications up to 400 VAC and can be supplied with wire leads or terminals. For similar performance, dry capacitors must use thicker dielectrics than oil-filled capacitors. Therefore, case sizes of dry capacitors are typically larger than oil-filled styles with similar design life performance. Plastic case dry capacitors are lighter weight than oil-filled units, and provide better corrosion resistance than metal case parts. Costs vary considerably depending on styles and quantities being compared. In general, plastic case parts with terminals offer lowest costs in higher quantities. However, oil-filled units may offer lower costs and quickest delivery for small quantities of off-the-shelf standard products.
Unprotected Dry Plastic Case Capacitors:
Aerovox dry plastic case capacitors can be supplied with insulated wire leads or terminals. Wire lead styles use suffix "-P" on capacitor part numbers. Wire leads are 8" long 18 gauge stranded copper wire with UL listed insulation rated for 150oC. Terminal styles use suffix "-PQ" and have standard single blade 1/4" quick-disconnects (like used on oil-filled capacitors). As clearly noted in this brochure, unprotected capacitors may fail short.
While oil-filled parts are only supplied with terminals, plastic case styles are made by Aerovox with terminals or wire leads. Wire leads are 8" long 18 gauge stranded copper wire with UL listed insulation rated for 150oC. Terminals are 1/4" wide x 1/32" thick standard electrical terminals that mate to connectors available from a variety of sources. Standard terminals are two-blade style on oil-filled metal cases (with ground lugs and three or four blade terminals available on special request). Standard terminals on Aerovox plastic cases are 1/4" single blades (two-blade available on special request).
Each Aerovox capacitor label includes the following information: AEROVOX, four-digit date code (yr/wk), uF (micro farads), VAC rating, our part numbers, and safety agency symbols. Special marking is also available. PROTECTED is clearly marked where that feature is included, otherwise NOT PROTECTED is shown on labels where plastic cases are unprotected. Dual-Section capacitors have Micro farads printed next to the terminal (common in middle).
Plastic case parts are labeled 100oC max. Standard oil-filled oval cases made by Aerovox which had been labeled 90oC can now also be labeled 100oC max (because these oil-filled capacitors perform as well on accelerated tests as plastic case capacitors labeled 100oC max).