ZN28-12C series indoor high-voltage vacuum circuit breakerDetailed product description：

1. Overview
The ZN28-12C indoor high-voltage handcart vacuum circuit breaker (hereinafter referred to as the circuit breaker) is a three-phase AC 50Hz indoor device equipped with a DC electromagnetic operating mechanism or spring operating mechanism. It is used as a circuit breaker for KYN1-12 and JYN2-12 indoor AC metal withdrawable switchgear and is suitable for power supply and distribution systems with a rated voltage of 12kV and below. Used as control or protection switches for electrical facilities in industrial and mining enterprises, power plants, and substations, especially suitable for places with frequent operations.
2. Normal usage conditions
a) Surrounding air temperature: not exceeding 40 ℃, and the average value measured within 24 hours does not exceed 35 ℃; The minimum ambient air temperature is -10 ℃;
b) Altitude: not exceeding 1000m;
c) The surrounding air is not significantly polluted by dust, smoke, corrosive and flammable gases, vapors, and salt spray;
d) Relative humidity: daily average not exceeding 95%, monthly average not exceeding+90%; The daily average value of water vapor pressure shall not exceed 2.2kPa, and the monthly average value shall not exceed 1.8kPa; During periods of high humidity, if the temperature drops sharply, condensation may occur;
e) Any requirements beyond the above conditions shall be agreed upon by the user and the manufacturing unit.

3. Main technical parameters of ZN28-12C series indoor high-voltage vacuum circuit breaker:

serial number	parameter name	unit	data
			20kA	25kA	31.5kA
one	rated voltage	kV	twelve
two	rated frequency	Hz	fifty
three	rated current	A	630, 1250	630, 1250, 1600	1250, 1600, 2000
four	Rated short-circuit breaking current	kA	twenty	twenty-five	thirty-one point five
five	Rated short-circuit breaking current breaking times	time	thirty
six	Rated short-circuit closing current (peak)	kA	fifty	sixty-three	eighty
seven	Rated dynamic stable current		fifty	sixty-three	eighty
eight	Rated thermal stability current		twenty	twenty-five	thirty-one point five
nine	Rated thermal stability time	s	four
ten	closing time		≤0.2
eleven	Opening time		≤0.06
twelve	1-minute power frequency withstand voltage	kV	forty-two
thirteen	Lightning impulse withstand voltage (peak value)		seventy-five
fourteen	Rated breaking current of a single capacitor bank	A	six hundred and thirty
fifteen	Rated back-to-back capacitor bank breaking current		four hundred
sixteen	mechanical life	time	ten thousand
seventeen	Rated operating sequence		0-0.3s-CO-180s-0
eighteen	Equipped with operating mechanism		CY17 Ⅰ, CT19 Ⅰ		CY17 Ⅱ, CT19 Ⅱ
nineteen	Rated operating voltage of the closing and opening coils of the operating mechanism	V	CD17：DC110、DC220 CT19：AC110、AC220、AC380、DC48、DC110、DC220
twenty	Contact opening distance	mm	11±1
twenty-one	overstroke		4±1
twenty-two	Allowable cumulative thickness of contact wear		three
twenty-three	Average closing speed	ms	0.6±0.2
twenty-four	Average opening speed	m/s	1.0±0.3		1.0±0.2
twenty-five	Three synchronous closing and opening of switches	ms	≤2
twenty-six	Contact closing bounce time		≤2
twenty-seven	Oil buffer stroke	mm	ten0+0.5

ZN28-12C series indoor high-voltage vacuum circuit breaker