57.4mm mounting hole submersible single phase circuit breaker used for 5-100KVA single phase oil type transformer at 120/240 volts
| Model | P2P21T110 |
| Rated Current | 21A |
| For Transformer | 5KVA/10KVA |
| Rated Voltage | 240V/480V |
| Trip Temp. | 110℃, 120℃, 130℃ |
| Phase | 1F |
🔴Our products come in two styles: straight handle and curved handle. Please contact us for more information.[📪nancywang@ketranele.com].
lt is three phase circuit breakers, used for three phase transformers. Circuit breaker are installed onthe secondary winding of the transformer, are used for over load protection and short circuit protection.
| Model | Current (A) | Rating (KVA) | Voltage (V) | Signal light | Emergency switch (overload) | Magnetic protection | Resistance (Ω) at 25°C 2 poles | Loss (W) at 85°C 2 poles |
|---|---|---|---|---|---|---|---|---|
| P2P21TXXX | 21 | 5 | 240 | Yes | Yes | No | 3800 | 2.1 |
| 10 | 480 | |||||||
| P2P42TXXX | 42 | 10 | 240 | Yes | Yes | No | 3200 | 7 |
| P2P63TXXX | 63 | 15 | 240 | Yes | Yes | No | 2100 | 10 |
| P2P105TXXX | 105 | 25 | 240 | Yes | Yes | No | 900 | 12 |
| 50 | 480 | |||||||
| P2P157TXXX | 157 | 37.5 | 240 | Yes | Yes | Yes | 800 | 24 |
| 75 | 480 | |||||||
| P2P210TXXX | 210 | 50 | 240 | Yes | Yes | Yes | 750 | 41 |
| 100 | 480 |
| Max Voltage | Power Frequency Test (one minute) 50/60HZ | Lightening Impulse Test | Insulation Resistance (5000V) | Normal Interrupting Capacity |
|---|---|---|---|---|
| 600V | ≥10KV | 30KV | ≥5000MΩ | 11KA~20KA |
| Model | Current (A) | Interrupting Capacity(KA) |
|---|---|---|
| P2P42TXXX | 42 | 4 |
| P2P63TXXX | 63 | 4 |
| P2P105TXXX | 105 | 7 |
| P2P157TXXX | 157 | 11 |
| P2P210TXXX | 210 | 11 |
(Trip temperature = Bi-metal trip temperature)
| No. | Bimetal ID | Current (I: A) | Bi-metal Ampere Response Factor (J: °C/A²) | Bi-metal temperature rise to oil (ΔT: °C) | Oil temperature (To: °C) | Bi-metal temperature (T: °C) |
|---|---|---|---|---|---|---|
| 01 | 21 | 21 | 0.0125000 | 5.5 | To | 5.5+To |
| 02 | 42 | 42 | 0.0040000 | 7.1 | To | 7.1+To |
| 03 | 63 | 63 | 0.0019904 | 7.9 | To | 7.9+To |
| 04 | 105 | 105 | 0.0008114 | 9.5 | To | 9.5+To |
| 05 | 157 | 157 | 0.0002000 | 4.9 | To | 4.9+To |
| 06 | 210 | 210 | 0.0001120 | 4.9 | To | 4.9+To |
T:Bi-metal temperature(℃ )
ΔT:Bi-metal temperature rise to oil(℃ )
To:oil temperature(℃)
I:Current flow through the Bi-metal trip in(A)
J:Bi-metal Ampere Response Factor in (J:℃ /A²)
ΔT=I²*J
T= ΔT+To
Note: When Bi-metal temperature reaches the trip temperature setting of the breaker,the breaker trip.
The following drawings show only partial product dimensions.
For the complete set of engineering drawings or full specifications, please contact us at [📪nancywang@ketranele.com].


Q1:How Does a CSP Circuit Breaker Work?
A1:Over current Protection Function: When the current exceeds the rated capacity, the thermal-magnetic trip mechanism detects overloads or short circuits.It automatically disconnects the circuit, preventing conductor overheating or equipment failure.
Q2:What are the advantages of oil-immersed circuit breakers compared to vacuum types?
A2: Oil-immersed circuit breakers provide better cooling, insulation, and resistance to outdoor environments, making them ideal for remote or harsh locations. Vacuum types are preferred for indoor or high-frequency switching applications.
Q3: What is the maintenance cycle for an oil-immersed CSP breaker?
A3:Routine oil sampling and mechanical inspection are recommended every 3–5 years; under normal operation, maintenance requirements are minimal.
Q4: What is the typical lead time for orders?
A4: Standard models are available in stock; customized orders usually require 3–4 weeks.