Farady produces neutral grounding resistors for 6-35kV AC networks. The resistors are installed in stainless steel cabinets and include an earthing transformer, resistor, and monitoring equipment. They limit fault overvoltage to within 2.6 times the phase voltage and improve relay protection. Standard models are available from 6-35kV with resistance values from 6-36 ohms and short time current ratings from 100-2000 amps. The cabinets have compact designs for easy installation and include high quality transformers and chromium alloy resistors.

1. Neutral grounding resistors
Product brochure
2010/4
Zhejiang Farady Electric Co., Ltd.
ISO9001&ISO14001 certificated enterprise

2. Product overview
++++General
Farady has own R & D team with outstanding technology and sophisticated equipment, advanced technology
introduction and digestion of foreign countries, long-term commitment to the production of neutral grounding
technology product research and development; to reduce the overvoltage and improve the safety and reliability of
the network.
Farady import special stainless steel alloy materials, development and production of a series of neutral grounding
resistors of the stainless steel cabinet, for 6 ~ 35kV AC network. In the system of cable power supply, the
grounding capacitance current is larger. When the current is greater than the specified value will be generated
when the arc grounding overvoltage. Injection of resistive current of the neutral grounding resistors mode is to
give the point of failure, the fault current is resistive and capacitive properties, reduce the phase difference and
voltage, reduce the fault current zero arc after the resignation rate, the overvoltage is limited within 2.6 times the
phase voltage, improve the sensitivity function the relay protection on the trip, in order to effectively protect the
normal operation of the system.
In the 6 ~ 35kV alternating current network, especially in the network with the cable power supply, the resistance
grounding is widely used. However, if the transformer winding is delta connection, neutral point grounding grid,
earthing transformer must be installed, and a resistor is arranged between the earthing transformer neutral point
and the ground.
FL-NGR transformer neutral grounding resistor cabinet is a farady with complete sets of equipment including
earthing transformer, the development requirements of these systems can be installed in the power plant power
system, substation power supply system, industrial and mining enterprises in the distribution system, the
realization of these grid uses in point via neutral grounding resistor system.
++++Service condition
1, Altitude: no more than 4000m
2, ambient temperature: -40 to +60 degrees
3, relative humidity: no more than 95% (25 degrees C)
4, the installation place: air does not contain chemical corrosion of gas and steam, no explosive dust
5, power grid frequency: 48 ~ 52Hz (50 Hz system), 58 ~ 62 Hz (60 Hz system)
6, applicable to: Indoor & Outdoor
7, resistance installation point: the normal state of the neutral point displacement does not exceed 3% of the
running phase voltage
Note: special conditions of use, please enquiry Farady tech dept during ordering
++++Product Feature
1, targeted, protection in place
FL-NGR transformer neutral grounding resistors cabinet is suitable for the system neutral point using small
resistance or neutral grounding of the occasion. At this point, the power grid has a single phase to ground fault,
the need for immediate trip to remove the fault line. When a single-phase grounding occurs in the power grid, the
grounding resistance provides additional resistance current to the ground, which causes the grounding current to
be in a resistance capacity, thereby ensuring that the overvoltage is not more than 2.6 times the phase voltage.
2, compact structure, easy to install
FL-NGR transformer neutral grounding resistor cabinet Z scattered earthing transformer (such as system without
neutral point is needed), resistor, current transformer, measuring

3. instrument, grounding protection output terminals and other electrical equipment integrated in a closed metal
cabinet, but also to selection of isolating switch, lightning arrester, complete delivery, high safety and reliability,
layout clear and tidy, convenient installation and debugging and maintenance.
3, material selection, fully guarantee the quality of products
FL-NGR transformer neutral point earthing transformer resistance cabinet for high-quality dry-type transformer,
the primary winding is "ZN" shaped stainless steel resistor wire; nickel chromium alloy (Cr20Ni80) material, its
high conductivity, flow ability, high temperature, maximum use temperature can reach 1600 DEG; low
temperature coefficient less than -0.045% / C, resistance stability, corrosion resistance, anti explosion, high
reliability. Resistance alloy material used in all resistance unit is welded into a frame structure with multiple units
using sub arc resistance unit adopts the high temperature resistant insulator (polymer) support connection.
According to different customer requirements, our company can provide import resistor.
4, monitoring function is complete, and provide analog output
FL-NGR transformer neutral grounding resistor cabinet can be equipped with a current transformer and the
normal action recorder, can monitor the unbalanced current in neutral point; single-phase ground fault, can record
the action times; and to the protection and monitoring system provides analog output; can also according to need
to install special lightning arrester.
5, strong technical force, and thoughtful service
Farady electric is a professional manufacturer, strong technical force, pre - technical exchanges and consultation
can be in place at any time. After sales installation technical guidance can be carried out in a timely manner
according to user requirements.
++++Standard model and parameter
Model
System rating
voltage(kV)
Short time flow current
（A）
Short time flow time
（S）
Rating
resistance
（Ω）
FL-NGR-6/36.4 6.3 100 10 36.4
FL-NGR-6/18.2 6.3 200 10 18.2
FL-NGR-6/9.09 6.3 400 10 9.09
FL-NGR-6/6.06 6.3 600 10 6.06
FL-NGR-10/15.16 10.5 400 10 15.16
FL-NGR-10/10.10 10.5 600 10 10.10
FL-NGR-10/7.57 10.5 800 10 7.57
FL-NGR-10/6.06 10.5 1000 10 6.06
FL-NGR-35/20.20 35 1000 10 20.20
FL-NGR-35/10.10 35 2000 10 10.10
P.S. We can design and manufacture all kinds of resistance according to user requirements, the
resistance value from 1 ohm -2000, allowing the error of the current 1A-2000A. resistance value of + 3%.
allows flow time 10s, 15s, 30s, 60s.

4. ++++Overall size and installation
1, equipment installation wiring diagram as shown below
2, the resistance cabinet can be fixed on the concrete foundation, to maintain the resistance level. The equipment
case should be grounded by the foot of the cabinet. The external dimension of the resistance cabinet is
determined according to the specific parameters of the user. The following is the outline size of FL-NGR-6/400:
NGR cabinet overall size 1200L x 1200W x 1900H(mm)

5. ++++Ordering instructions
Please advise the following parameters when ordering.
1 system rated voltage: (kV)
2 short term allowable current: (A)
3 nominal resistance value: (Ohm)
4 whether the installation of current transformer (CT): CT ratio and capacity, composite tolerance
6 incoming and outgoing type:above comer,buttom feeder,buttom incomer,buttom feeder,optional;
7 short time allowed flow time: (S)
The resistor cabinet material,
8 (IP) level of protection, color code and installation site;
9 do you need to install the ground record and temperature and humidity control device.
Copyright 2014 Farady Electric
Zhejiang Farady Electric Co.,Ltd
TEL:0086-577-61722510/61777258
Fax:0086-577-61777257
Http://www.farady-electric.com
Email:info@farady.cn
Add:NO.81,Sutai Road,Su’ao,Liushi,Yueqing,Zhejiang,China,325604