Seller New Technology Ngr Neutral Grounding Resistor To Power Distribution Box
General product information
1. Neutral Grounding Resistor Standards Carried-Out:DI/780 -2001
distribution system neutral grounding resistor
GB6450
dry-type power transformer
DI/T620-1997
Overvoltage protection and insulation coordination of AC electrical equipment
GB/T16927-1997
high voltage testing technology
GB1208-1997
current transformer
GB4208-93
case protection grade
IEEE32-1972
Technologies ,terms, and experiments of neutral grounding equipments
GB311.1-1997
insulation coordination of high voltage transmission and distribution device
DL/T593-1996
common ordering technical conditions of high voltage switch device
GB50150-1991
standards of electrical equipment handing-over and experiment of electrical device installment project
2.Operation Conditions:
FUNCTION
Neutral Grounding Resistors are used to protect power transformers, power generators and other associated equipment in your power systems against 50/60 Hz faults (short circuit) and transient phenomena (lightning).
SPECIFICATIONS
There are six parameters needed to specify the neutral grounding resistor.
1. Rated voltage line to neutral or system voltage.
2. Rated fault current.
3. Rated 'duration time' of the line to neutral voltage not exceeding the allowable temperature rise.
4. Rated Resistance.
5. Application environment, indoor or outdoor.
6. Enclosure material, ss plate or normal cold rolled sheet.
RANGE
o Rated current: from 1 amp to 2000 A
o Rated voltage: from 6 to 20kV
o Rated Resistance: from 1 ohm to 2000 ohm
o Rated time: 1 sec to continuous time rating
TESTING AND QUALITY
with IEEE-32. Routine tests performed on each Neutral Grounding Resistor are measurement of resistance, high voltage power frequency, insulation measurement, aspect verification, dimensional control. Mingrui's internal quality system has been developed and certified under ISO 9001 quality system
CONSTRUCTION
Standard unit includes the stainless steel resistor assembly plus all the required insulators, internal connections and hardware installed in a standard safety enclosure. Neutral Grounding Resistor units are completely assembled, prewired, and tested at our facility. For shipping all units are crated for added protection and ease of handling.
ENCLOSURE FEATURES
o Forged eyebolts in all four corners for easy hoisting.
o Removable front and rear louvered covers for easy access for connection and inspection.
o Corrosion resistant nameplate provides complete ratings and manufacturers *vy gauged enclosure polyester powder coated finish provides maximum protection.
ENCLOSURE OPTIONS
oStainless steel, cold rolled plate construction. Custom paint finish is available.
o Top or side mounted entrance bushing(s).
o Screened covers for indoor applications.
o Support stands for elevating the enclosure above ground.
OPTIONS
Current or potential transformers mounted and prewired at our facility
ON or OFF Load disconnecting switches
3.Parameters of Grounding Transformer
Insulation Grade: H
Cooling-down Method: AN
Temperature Rise =300 M?, low voltage to grounding >=100 100 M?
4.Ordering Instructions
To serve you better, please kindly offer following information when ordering
6.1 generator rated voltage, transformation ratio of grounding transformer, resistance value;
6.2 insulation form of grounding transformer;
6.3 transformation ratio of current transformer ;
6.4 color of cabinet, wiring from the top or bottom;
6.5 time of current flowing-through
6.6 material and color of box, IP protective grade, colour and installation *ce for purchase:
1. system rated voltage
2.short-time withstand current;
3. normal resistance;
4. with current transformer or not; transformation ratio, capacity and compound deviation of the current transformer;
5. method of wiring (optional): a. wire in from the top, and out at the bottom, b. wire in and out from the bottom, c. wire in and out from the side, d. wire in from the side and out at the bottom;
6. durable time for short-time withstand current;
7. material of resistance cabinet, protection grade of (IP), color code and installation site of the resistor cabinet;
8. with earthing record and temperature and humidity control equipment or not