One-way service shields ЩО-70 and ЩО-91

SHO-70 and SHO-91

Panels ЩО91 and ЩО70 are used in the assembly of distribution boards with a solidly earthed neutral for transformer substations, RUNN and GRSh.

Purpose:

Panels ЩО91 and ЩО70 are used in the assembly of distribution boards with a solidly earthed neutral for transformer substations, RUNN and GRSh. 

Scope and conditions of application:

Shields assembled from panels ЩО-70 and ЩО 90 can be used in electrical rooms of industrial, administrative, public buildings, industrial facilities and civil engineering projects.
The device is intended for operation in the following conditions:
 • climatic version of panels – У, placement category 3 according to GOST 15150;
 • operating temperature range – from -40°С to +50°С;
 • panels are intended for installation in closed rooms with natural ventilation;
 • without artificially controlled climatic conditions;
 • the environment must be non-explosive, do not contain aggressive gases and vapors;
 • the environment must not be saturated with conductive dust, water vapor.
Design:

According to their purpose, the ЩО panels are divided into:

• linear;
• introductory;
• sectional;
• introductory-linear;
• introductory-sectional;
• panels with ATS equipment;
• metering boards.

Functions of panels ShchO-70, ShchO-91 

• reception, distribution and metering of electric power in three-phase alternating current networks up to 4000 A, voltage 380/220 V, 50 Hz; 
• protection of outgoing lines during overloads and short circuits; 
• infrequent operational switching of electrical circuits. 

Sectional panel:

• serves to connect one section of the shield to another when the voltage disappears at one of the two inputs; 
• has a switch with a lever drive of the BP series (it is installed on the front of the panel) or an automatic switch with an electromagnetic drive. 

Input-line panel:

• is a combination of input and linear panels for cable and busbar entries; 
• has a switch and fuses in the input part; 
• has switches and fuses in the linear part; 
• contains current transformers and measuring instruments. 

Input section panel:

• is a combination of input and sectional panels for cable and busbar entry; 
• has switches and fuses at the inputs; 
• has a switch with a central drive as a section switch; 
• contains current transformers and measuring instruments. 

Panel with ATS equipment:

• used in a two-transformer substation with automatic reserve switching; 
• is located between the input and section panels of the distribution board. 
• The panel contains control equipment for input and sectional circuit breakers. 

Metering panel:

- is used to account for active and reactive electric energy; 
- has metering devices, a lamp and windows for readings. 
The panel is installed on the wall of the room. 

Classification of panels ShchO-70, ShchO-91 

The ЩО panels are divided into linear, input, sectional, input-linear, panels with ATS, and street lighting dispatch control panels.
The ЩО70 and ЩО91 panels are welded metal structures with one-sided service.
The panels are closed with a metal door with locks from the front and with walls from the back and sides. Switching equipment is installed on profiles inside the panels.

Distribution boards ЩО-70 and ЩО-91

• Power is supplied to the ЩО-91 and ЩО-70 panels through the input panels, from below. 
• The outgoing conductors are fixed to the linear panels, also from below. 
• Distribution of electrical energy within the panels of the switchboard is carried out using a set of busbars. 
• In the sectional panel, the switchboard inputs are reconnected when power is lost in one of them. 
• The sides of the distribution boards are covered with end panels.

Operating conditions of panels ЩО-70 and ЩО-91:

• Panels ЩО-91 and ЩО-70 are intended for installation in rooms with an industrial type of atmosphere. 
• They are produced in the U3 version and have a protection rating of IP20 on the facade (protection against access to live parts). 

Main technical data of the panels of the ЩО series

Power supply circuit parameters: ~ 3x380/220 V, 50 Hz.
Nominal current: up to 4000 A
Nominal operating mode – continuous
Established service life – at least 25 years
Established mean time between failures – at least 9000 hours.

Features of the ЩО series panels

• Electrodynamic resistance to short-circuit currents: for panels ЩО-70-1: 30 kA for panels ЩО-70-2, ЩО-70-3, ЩО-91: 50 kA
• Panels ЩО-70-1 are used to complete distribution boards with a capacity of up to 630 kVA
• Panels ЩО-70-2, ЩО-70-3, ЩО-91 are used to complete distribution boards with a capacity of over 630 kVA
• The housings of the ЩО-70-3 and ЩО-91 panels, unlike ЩО-70-1 and ЩО-70-2, have smaller dimensions and metal content. 

Structure of the conventional designation of the panel ЩО-70-Х-ХХ У3:

Technical specifications:

When operating ground products, the upper working value of atmospheric pressure is 106.7 kPa (800 mm Hg). For products not intended for operation in high-altitude areas (the normal altitude above sea level does not exceed 1000 m), the lower working value of atmospheric pressure is 86.6 kPa (650 mm Hg), the lower limit working value is 84.0 kPa (630 mm Hg). For aircraft, as well as for products intended for operation at altitudes above 1000 m at reduced atmospheric pressure (including products intended for operation both at altitudes above 1000 m and at altitudes of up to 1000 m, or in high-altitude areas), the average and lower working values ​​of atmospheric pressure depending on the altitude above sea level are taken in accordance with Appendix 7, Table 1. Standards or technical specifications for such products indicate the pressure value or reduced pressure group, or altitude. 

Secondary equipment – ​​equipment (apparatus, devices, complexes) of the automated control system, fire-fighting system, security alarm, video surveillance, OPT, 0.4 kV AC auxiliary needs system, auxiliary equipment control and alarm systems, etc.

The devices installed on the transformer substation must be located on the front side for easy observation of their readings. Other arrangements of the devices are allowed upon agreement with the consumer.