Application note: MCB versus MCCB
A circuit breaker is the key to a safe system for the disconnection of the power supply in case of overload or short
circuit. There are two types of circuit breakers generally used i.e.:
Moulded Case Circuit Breaker (MCCB)
Miniature Circuit Breaker (MCB)
Characteristics of MCB’s:
Low price (compared to MCCB’s)
Require small space
Currents up to 125A
Characteristics of MCCB’s:
Very high price (compared to MCB’s)
Require large space
Currents up to 1600 A
Maximum current trough the circuit breaker is adjustable
Main effects of using MCCB’s instead of MCB’s:
More space required
The enclosure in which a MCCB will be mounted is larger due to the larger size of the MCCB. This may result
in requiring more enclosures and interconnections. Especially for offshore platforms this may cause a
problem due to the generally limited available space on a platform.
Higher cost
More and/or larger enclosures increase the costs substantially. Moreover MCCB’s are much more expensive
than MCB’s.
As generally currents in solar power systems and to the connected loads are (well) below 125A and the functionality
of a MCB is same as or similar to a MCCB. In order to save costs and space Tss4U recommends to use MCB’s where
possible.
Circuit Breaker comparison table (examples)
Output circuit
breaker
Battery circuit
breaker
Battery circuit
breaker
MCB S 202 C25
MCB S802 C125
MCCB Tmax T2S R125
1
5.3
7.4
35x69x88 mm
53x95x88 mm
120x70x130 mm
212 cm³
443 cm³
1092 cm³
Rated current max
25A
125A
160A
Icu max
20KA
50KA
85KA
Electrical life
(no. of operations)
10000
10000
8000
Weight
250 g
490 g
1100 g
Type
Price (factor)
Dimensions (WxDxH)
Volume
Source: ABB
Tss4U B.V.
The Netherlands
Looyenbeemd 3a
5652 BH Eindhoven
Tel:
Fax:
+31 40 235 1702
+31 40 235 1881
info@tss4u.nl
www.tss4u.nl
15-11-2013
CoC 17156182
VAT No: NL8120.42.530.B01