Although there are exceptions, most of the time a fuse needs to be installed into some sort of panel mounted, PCB mounted and inline fuseholders, fuse blocks or fuse clips (collectively known as "fuseholders" for purposes of this discusion).
Fuseholders are typically classifed into two distinct types:
- Fuseholders that are intended to be used at low voltages - such as automotive applications.
- Fuseholders that are intended to be used at line voltages such as applicances and factory equipment.
- So lets look at the two possiblilities. If the voltage is low...say 12 or 24 volts...then a user cannot be readily shocked becuase there is not enough critical voltage to pass through the human body.
- If the voltage is higher, say 120 or 240 volts, then there is enough voltage to pass through the human body and create a shock.
According to IEC (IEC 60065 & 60127), an electrical shock due to a fuseholder can occur when either of following two events occur.
- The dielectric strength (resistance) of the fuseholder material is not high enough for the applied voltage therefore electrical current is able to pass through the plastic material.
- The user can readily touch a metal component connected to the voltage source.
So in order for a fuseholder to be considered "shock-safe", the fuseholder material must best selected so that the dielectric of the material (resistance) higher than the applied voltage AND there should be no exposed metal part that a user could accidentally touch.
As for the first part, all OptiFuse "shock-safe" fuseholders are designed using high-temperature plastic material (UL94-VO) with dielectric strengths allowing upwards to 2,000 volts to be applied before any leakage current occurs..
Additionally, no metal parts on the fuseholder body or cap are left exposed to the user. This prevents an electrical shock accidental from occuring.
Lastly, when the fuseholder cap is removed from the body of a shock-safe fuseholder, the fuse should remain with the cap. This allows the fuse to be safely removed from the fuseholder. Removing the fuse in this way prevents the user from accidentally touching the fuse, causing an electrical shock.
When applied properly, fuses and fuseholders provide additional safety for equipment and personnel.
Thank you once again for your continued support of OptiFuse where as we try to create safe as well as functional products...