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Submersible 157 Single Phase 1F Circuit Breaker [35mm]

Model: M2P157T110: 110℃; 120℃; 130℃

57.4mm mounting hole submersible single phase circuit breaker used for 5-100KVA single phase oil type transformer at 120/240 volts

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Low loss, High interrupting capabllity

Resetting Mechanlsm&Emergency Control, Easy for Malntalnance

Complete Certification

Specifications

Model	M2P157T110
Rated Current	157A
For Transformer	37.5KVA/75KVA
Rated Voltage	240V/480V
Trip Temp.	110℃, 120℃, 130℃
Phase	1F

Standards Product Dimension Video & Photos FAQS

Standards

❖ Standards for Reference:

ANSI C 57.109-2018 (Revision of lEEE Std c57.109-1993) lEEE Guide for liguid-immersed Transformer.
Through-Fault-Current Duration.
lEEE Standard C37.91 -2008, lEEE Guide for Protecting Power Transformers.
lEEE Standard C57.91-2011/IEEE C57.12.00-2015 /EEE C57.12.90-2015.
IEEE C37.13-2015 /EEE C37.50-2018.
IEC60947-2:2016+AMD1:2019 Part 2:Circuit-breakers.
PLN D30.002-2008(Indonesia)Specification for CSP transformers.

❶ Specification and Data Sheet

It is single phase circuit breakers, used for single phase transformers. Circuit breaker is installed on the secondary winding of the transformer, is 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
M2P21TXXX	21	5	240	Yes	Yes	No	3800	2.1
M2P21TXXX	21	10	480	Yes	Yes	No	3800	2.1
M2P42TXXX	42	10	240	Yes	Yes	No	3200	7
M2P63TXXX	63	15	240	Yes	Yes	No	2100	10
M2P105TXXX	105	25	240	Yes	Yes	No	900	12
M2P105TXXX	105	50	480	Yes	Yes	No	900	12
M2P157TXXX	157	37.5	240	Yes	Yes	Yes	800	24
M2P157TXXX	157	75	280	Yes	Yes	Yes	800	24
M2P210TXXX	210	50	240	Yes	Yes	Yes	750	41
M2P210TXXX	210	100	280	Yes	Yes	Yes	750	41
M2P313TXXX	313	75	240	Yes	Yes	Yes	500	60
M2P313TXXX	313	150	480	Yes	Yes	Yes	500	60
M2P420TXXX	420	100	240	Yes	Yes	Yes	450	98
M2P420TXXX	420	200	480	Yes	Yes	Yes	450	98

Note:

2P42TXX,"2P" means 2 poles, "42" means current, "TXXX" means trip temperature, for example "T120" means the trip temperature is 120℃ , Temperature can be setted from 90 to 130 degree, with +/-10% tolerance.
And there are +10% tolerance for resistance and losses,emerency tolerance: +/-10%.

❷ Electrical specification for all CSP Oil Type Circuit Breaker

Max Voltage	Power Frequency Test (one minute) 50/60HZ	Lightening Impulse Test	Insulation Resistance (5000V)	Normal Interrupting Capacity
600V	≥10KV	30KV	≥5000MΩ	11KA~20KA

❸ Interrupting Capacity

Model	Current (A)	Interrupting Capacity(KA)
M2P42TXXX	42	4
M2P42TXXX	42	4
M2P63TXXX	63	4
M2P105TXXX	110	7
M2P157TXXX	157	11
M2P157TXXX	157	11
M2P210TXXX	210	11
M2P210TXXX	210	11
M2P313TXXX	313	20
M2P420TXXX	420	20

❹ Trip Temperature and Bi-metal Temperature Rise to Oil

(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
07	313	313	0.0000610	6.0	To	6.0+To
08	420	420	0.0000720	12.5	To	12.5+To
09	433	433	0.0000720	13.5	To	13.5+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.

Product Dimension

Key Dimensions Overview

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].
Video & Photos

Installation Video

Application
FAQS

Q1: What is an underground oil-immersed CSP circuit breaker?

A1: It is a low-voltage protection device installed inside underground or sumbersible transformers, used to control and protect the transformer’s secondary circuit.

Q2: What are its main functions?

A2:It automatically disconnects the low-voltage circuit in case of overload or short circuit to protect the transformer and connected equipment.

Q3: What are the advantages of an underground CSP breaker?

A3:The oil-immersed design provides excellent insulation, high reliability, and maintenance-free operation suitable for sealed or underground environments.

Q4: Can it be customized for different transformer types?

A4: Yes, customized models are available for single-phase or three-phase underground transformers with various capacities.