WTB1-63 AC Circuit breaker
WTB1-63 1-4P ACCB with residual current protection. 4-pole, 20A rated.
AC Circuit breaker
AC miniature and molded breakers designed for overload and short-circuit protection in AC distribution networks.
AC Circuit breaker products
DZ47LE-63 4P 20A RCCB Wholesale
DZ47LE-63 4P 20A RCCB with residual current protection. 4-pole, 20A rated.
DZ47LE-63 2P 63A RCCB Wholesale
DZ47LE-63 2P 63A RCCB. Residual current protection, 2-pole, 63A rated.
DZ47LE-63 3P 63A RCCB Wholesale
DZ47LE-63 3P 63A RCCB. Residual current protection, 3-pole, 63A rated.
DZ47-125 2P 100A High Miniature Circuit Breaker MCB
DZ47-125 2P 100A MCB. High breaking capacity, thermoplastic shell, 2-pole design.
DZ47-63 4P 63A Miniature Circuit Breaker MCB
DZ47-63 4P 63A MCB. Compact 4-pole design, wide current choices, flame retardant casing.
DZ47LE-63 1P 20A RCCB Wholesale
DZ47LE-63 1P 20A RCCB. Residual current protection, 1-pole, 20A rated.
DZ47-125 4P 100A High Miniature Circuit Breaker MCB
DZ47-125 4P 100A MCB. High breaking capacity, thermoplastic shell, 4-pole design.
DZ47LE-125 4P 100A RCCB Wholesale
DZ47LE-125 4P 100A RCCB. Residual current protection, 4-pole, 100A rated.
Sizing a Breaker for an AC Unit?
Send the nameplate minimum circuit ampacity and maximum breaker size, or the circuit list for a board. We reply within 24 hours with the model, curve and pole count.
AC CIRCUIT BREAKERS
AC Circuit Breakers for Air-Conditioning Circuits and Distribution Boards
The term AC circuit breaker covers two different things. In the US it usually means the breaker feeding an air-conditioning condenser; in a panel schedule it means a breaker for alternating current, as opposed to a DC-rated device. Both are miniature breakers with a thermal-magnetic trip, and both are in this category.
DZ47-63 covers 2-pole and 4-pole circuits at 63 A with 4,500 A breaking capacity at 230/400 V. DZ47-125 extends to 100 A, DZ47LE adds residual current protection at 30, 100 or 300 mA from one pole to four, and WTB1-63 covers 6 A to 63 A with 4 kA and 6 kA options.
For an air-conditioning condenser, the breaker is sized on the circuit minimum ampacity and the maximum fuse rating on the unit nameplate, with a C curve to ride the compressor inrush. Units carry CE and CCC marking.
Sizing an AC Breaker
For an air-conditioning circuit, take the two numbers from the unit nameplate: minimum circuit ampacity and maximum fuse or breaker size. For a distribution circuit, size on the cable.| Circuit | Typical breaker | Curve | Note |
|---|---|---|---|
| Small split AC, 230 V | 2P 16–25 A | C | Follow nameplate MCA |
| Large split or ducted | 2P 32–40 A | C | Compressor inrush |
| Three-phase condenser | 4P 25–63 A | C or D | Check phase balance |
| Lighting circuit | 1P 10–16 A | B | Long cable runs |
| Socket circuit with RCD | 2P 16–32 A + 30 mA | C | DZ47LE |
Curve choice
- B curve trips at three to five times rating: lighting, long cables, resistive loads.
- C curve trips at five to ten times: motors, compressors, general mixed loads.
- D curve trips at ten to twenty times: welders, transformers, high-inrush equipment.
Sizing for Air-Conditioning, Not for Lighting
The Nameplate Beats a Rule of Thumb
Use minimum circuit ampacity and maximum breaker size from the unit, not a guess based on the room size.
C Curve for Compressor Inrush
Starting current runs five to eight times the running current. A B curve trips on a healthy unit.
An RCCB Is Not a Breaker
Earth leakage protection does not clear an overload. Air-conditioning circuits usually need both.
COMMON QUESTIONS
Frequently Asked Questions
Use the two numbers on the unit nameplate: minimum circuit ampacity and maximum fuse or breaker size. The breaker must sit at or below the maximum and at or above the minimum ampacity. A typical 230 V split unit lands on a 2-pole 16 to 25 A breaker with a C curve, but the nameplate always governs.
Three common causes: a compressor drawing locked-rotor current because it is failing, a condenser coil that is dirty enough to raise head pressure and current, or a breaker that is undersized for the unit. Measure the running current against the nameplate; if it is close to the rating, the fault is in the unit, not the breaker.
An AC breaker clears the arc when the current crosses zero, which happens twice per cycle. DC never crosses zero, so a DC breaker needs a deeper arc chamber and a wider contact gap. The two are not interchangeable, and an AC breaker on a DC circuit may fail to clear a fault.
It is the short-circuit current the breaker can interrupt without being destroyed. If the fault level at the board is higher than the rating, the breaker may not clear the fault safely. Check the prospective fault current before choosing.
A 1P+N device breaks the live pole and switches the neutral without a rated breaking capacity in the neutral. A 2P device breaks both poles and is used where the neutral has to be isolated, which is common on air-conditioning circuits fed from a sub-board.
No. Each circuit needs its own protection sized to its cable and load. A shared breaker means the smaller cable is protected by a device rated for the larger load, which is exactly the condition a breaker is supposed to prevent.
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Send your application, voltage, certifications and quantity to this electrical protection manufacturer. We reply with a quotation within 24 hours.
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