What is SCCR value?
A short-circuit current rating (SCCR)1 is the maximum current a device or system can safely withstand for a specified time (such as 0.05 seconds), or until a specified fuse or circuit breaker opens and clears the circuit. SCCR is usually expressed in kiloamperes (kA).
How do I calculate SCCR rating?
SCCR is usually marked on the component, combination ratings are available on the UL website, or with the manufacturer’s instructions. If not available from the manufacturer, the SCCR value can be determined by using UL Table SB4.
What is the SCCR of a fuse?
The SCCR is the maximum current (in amps) that an electrical device or control panel is able to withstand for three (3) VAC electrical cycles, or during the operation of an over-current protection device such as a fuse.
What does SCCR mean in electrical?
Short-Circuit Current Rating
Components that provide functions other than overcurrent protection, such as disconnects, power distribution blocks, motor controllers and others, are required to achieve adequate Short-Circuit Current Rating (SCCR) (NEC 110.10).
Do Motors have SCCR rating?
Short-Circuit Current Ratings Defined SCCR applies to all electrical equipment, such as panelboards, switchboards, motor control centers and industrial control panels.
Is AIC and SCCR the same?
Note: The difference between SCCR and AIC is that AIC applies to overcurrent protection devices only, and the SCCR applies to the entire assembled device, which may use as part of its assembly overcurrent protection devices with an AIC rating.
Is AIC the same as SCCR?
Are the terms AIC and SCCR interchangeable? No! AIC applies only to overcurrent protection devices (circuit breakers, fuses, etc.), and SCCR applies to a fully assembled device (i.e., Lutron panel), which may use specific AIC-rated overcurrent protection devices.
How do I calculate SCCR in Control Panel?
- What is SCCR?
- Determining a panel’s SCCR.
- Step 1 – Determine the short circuit current rating of each component in the power circuit.
- Step 2 – Determine whether feeder circuit components limit fault current.
- Step 3 – Determine overall short circuit current ratings.
What is SCCR used for?
Definition: Short Circuit Current Rating (SCCR) is a rating on components and assemblies representing the maximum level of short-circuit current that a component or assembly can withstand. This rating is used to determine compliance with NEC 110.10. “SCCR” labeling is required on all panels and assemblies.
What does 22k AIC mean?
A breaker marked 22k AIC will protect anything it supplies so that the equipment never sees more than 22,000 amps of fault current.
What is the AIC rating of a 200 amp panel?
An example would be a 200-amp circuit breaker or fuse with an ampere interrupting capacity (AIC rating) of 42k AIC or 42,000 amps, installed in a panelboard where there is 38,000 amps of available fault current.
What unit is SCCR?
The Short Circuit Current Rating (SCCR) states the maximum amperage (fault current) a component, enclosure, or unit can withstand during a short circuit event thereby limiting personal injury, damage to the premises, and damage to equipment.
Do I need to mark the SCCR on my Industrial Panel?
If the industrial control panel contains only control circuit components, marking the SCCR is not required (also noted in NEC section 409.110 (4) Exception). Test a panel to achieve ratings higher than the value determined using Supplement SB.
What does the SCCR value represent?
SCCR represents the maximum amount of current that the assembly can safely withstand under short-circuit conditions. Additionally, the following general statement related to SCCR is included in NEC 110.10:
Where is the SCCR on the industrial machinery main nameplate?
However, the industrial machinery main nameplate and overall SCCR will be marked on the panel connected to the supply conductors from the facility.
Can the SCCR of a transformer be increased?
When transformers are used, both the branch-circuit overcurrent device interrupting rating and the component SCCR are able to be increased. However, when current-limiting overcurrent devices are used, only the component SCCR can be increased.
