CHỐNG SÉT POLYMERIC

Features:

• Morstar arresters have mold-on polymer housing for the ultimate seal against moisture ingress
• High strength Fiberglass for high fault-withstand design

Integrated Ground Lead Disconnet for fast, reliable operation.  Operates in less than 2 seconds at 5 amps and less than 2 cycles at 1,000 amps. As a special supporting product for arrester, the disconnector is series connected with arrester. When the arrester comes across any fault, it would operate quickly and let the failed arrester disconnect from the power grid, meanwhile, it would give obvious disconnection symbol, so that the maintenance personnel would find the point of failure and change the arrester in time. On the other hand, when the arrester works normally, disconnector does not work and is under low impedance state, it would not affect the protective characteristics of arrester. The arresters that have been equipped with disconnectors really realize safe operation, maintenance free, convenient and reliable performance.It is popular to use disconnectors for distribution type, power station type and line type arresters in power grid in Japan, occident countries and other developed countries and districts.The disconnectors produced by out company adopt the latest thermal-explosion design, with advantages of fast response and misoperation free, can be equipped with arresters of various models of 3kV above, having the same operating conditions with that of arresters.
Continuous Voltage
A preliminary selection that is based on selecting an arrester having a “Continuous Operating Voltage”, or Uc, that equals or exceeds the normal system maximum line-to-earth operating voltage is made. Reference IEC 60099-5.
 
Power-Frequency Overvoltages
The second application criterion to be met is a condition established by the effectiveness of system grounding. During a single line-to-earth fault, under maximum system voltage conditions, the arrester selected should have a “Rating” (Ur) that will not be exceeded by the voltages on the unfaulted phases at the point of arrester application. One must pay particular attention to systems having low coefficients of grounding, ungrounded systems and systems that are resonant grounded or that may become ungrounded under abnormal conditions of operation. This second voltage consideration may be modified for various system conditions as long as the application does not violate the selected arrester’s “Temporary Overvoltage Capability (TOV)” .Temporary system conditions resulting in sinusoidal power-frequency voltages that exceed arrester “Continuous Operating Voltage, (Uc)” or even “Arrester Rating, (Ur)” can be allowed. Consider the permissible magnitude and duration of these overvoltages (including the full time of system back-up protection), with appropriate allowances for any recent arrester discharge energies.The voltage withstand capability application on ungrounded systems is 1.035 per unit of COV (Uc) for 24 hours. Systems which permit earth faults to remain undetected or operate with one phase earthed for periods in excess of 24 hours will require the use of an arrester having aUc (continuous capability) equal to the system maximum phase-to-phase voltage.
Under some special system conditions, such as transformer energization using certain types of connections and ferroresonance, higher voltages can be experienced by the arrester. To ensure that the arrester's capabilities will not be exceeded, the resources of systems application engineers are available to make recommendations.
 
Performance:
            There are two series for The designs are tested in accordance with the latest ANSI/IEEE  standards for metal oxide arresters.
  

	series MSLA-10	series MSLA-05
01`	High Currect - Sort Duration   100kA	High Currect - Sort Duration   65kA
02	Low Current - Lon Duration  250 amps	Low Current - Lon Duration  150 amps
03	Nominal discharge class per IEC  10kA	Nominal discharge class per IEC  5kA
04	Duty Cycle - 10kA	Duty Cycle - 10kA
05	Line Discharge Class per IEC:  Class 1	Line Discharge Class per IEC:  Class 1
06	Minimum Energy Capability - 100% production tests: 2.7kJ/kV	Minimum Energy Capability - 100% production tests: 2.7kJ/kV
07	Fault Withstand Capability:  20kA	Fault Withstand Capability:  20kA rms-sym
08	REA Listed	REA Listed

Technical specification:Surge Arresters 5 kA and 10 kA for MV Systems to 36 kV

Nomal Duty Protective Characteristics Type MSLA-05kA
Catalog number	Rated Voltage   (Ur)	Maximun Continuous Operating Voltage MCOV (Uc)	Current impulse residual voltage			2000 µs  Rectangular   current impulse withstand	4/10µs High   current impulse   withstand	Creepage distance	Dimension
			1/4µ s   Steep   Current   impulse	8/20µ s   Lightning   current   impulse	30/60µ s Switching current impulse				A	B
	kV(rms)	kV(rms)	kV(crest)	kV(crest)	kV(crest)	kV(crest)	kV(crest)	(mm)	(mm)	(mm)
MSLA-0503	3	2.55	9.5	9.5	7.7	150	65	335	230	120
MSLA-0506