Panels of distribution boards
Panels of distribution boards of ЩО-70-У3 series are designed for assembling distribution boards of three-phase alternating current of 380/220 V with the frequency 50 Hz and are used for receiving and distribution of electric power, protection against overloads and short circuits and are used for installation in distribution networks in four-wire and five-wire design, with operating neutral and protection earthing conductors for automatic switching to the reserve supply of the lighting circuits and power electric equipment at the disappearance of normal supply voltage.
Panel ЩО-70(91) is a pressed-welded carcass with a door, which can be locked. Inside the carcass, on the brackets, there is a frame with equipment, which is controlled by the devices installed on the front studs of the carcass (automatic breakers of the line panels are controlled through the windows in the door).
For the fastening of the collecting busbars, in the upper part of the panel there is a bracket with insulators. On the facade of the upper cope of the panel, there is a control panel which is also a guarding of the collecting busbars. For the fastening of suitable cables and wires, there is a perforated L-bar, welded to the bottom belt of the carcass. Assembling panels into a board is carried out using bolted joints through the holes in the studs of the panels.
Collecting busbars are completed with busbars made of aluminum alloy with the cross section up to 2 mm. The cross section of the collecting busbars should be marked in the distribution device order form. Collecting busbars are located in the upper part of the board in the horizontal plane and are fastened onto the insulators. Collecting and neutral busbars are supplied joint for 2, 3, 4 panels. With the order of the distribution device of the two-row design, a busbar bridge can be also supplied with the panels. Necessity of its supply, as well as its length, should be discussed beforehand. Depending on the designation, ЩО are divided into lead-in, line, sectional, lead-in-line, lead-in-sectional, panels with ABP equipment, panels of the dispatcher control over street lighting, accounting panels, and special panels (in ЩО-70-3ат) series.
Panels are manufactured for cable inputs, as well as for busbar inputs with knife switches or automatic breakers. On the panels with knife switches, a knife switcher and protection devices for 630 A are installed (for 1000 A only a knife switch is installed). On the panels with automatic breakers, stationary breakers of BA55 series are installed for the currents of 1000, 1600, 2000 A with electromagnetic drive, and between the collecting busbars and the breaker disconnectors for 600, 1000, 1600 and 2000 A, controlled by the bar, are installed. For the service convenience, current transformers in these panels are placed between the breaker and the disconnector. There are no disconnectors between the input and the automatic breaker. In this case, for the maintenance of the breakers, a power transformer should be cut off from any high voltage.
On the outgoing lines of the panels, switching protection equipment and a current transformer and an ammeter for one phase of the outgoing lines are mounted. Panels are manufactured with the knife switches and protection devices or with automatic breakers. On the panels with knife switches, knife switchers and protection devices for 100, 250, 400 and 630 A are installed. On the panels with automatic breakers – breakers for the rated current 100, 250, 630 A stationary, with manual drive, also of BA55(3) series with electromagnetic drive for the rated current 1000 A.
Panels with automatic breakers are manufactured with the disconnector between the collecting busbars and the breaker (for maintenance) and also without it.
Sectional panels are design for the connection of one of the board sections to another section in case of voltage disappearance at one of two inputs. Panels are manufactured with knife switches or automatic breakers. In the panels with knife switches, a knife switcher is installed for 630, 1000 A with lever drive, which is mounted on the facade of the panel.
On the panels with automatic breakers, breakers of BA55(3) series are installed for the rated current of 1000A with electromagnetic drive, and on both sides of the breaker disconnectors for the rated current of 1000A, controlled by the bar, are installed for the maintenance.
These panels are a combination of lead-in and sectional panels and are manufactured for the cable and the busbar inputs. On the inputs a knife switcher and protection devices for the rated current of 630 A are installed, and a knife switch with central drive for 630 A is used as a sectional breaker. In the panel there are also installed current transformers and measuring devices.
Panel with ABP equipment
Panel is designed for the two-transformer substation, where it is necessary to provide an automatic reserve switching on. In the panel there is control equipment for the input and sectional automatic breakers; this equipment is installed between the input and sectional panels of the distribution device.
These panels are a combination of lead-in and line panels and are manufactured for the cable and the busbar inputs. In the input part of the panel, a knife switcher and protection devices for the rated current of 630 A are installed, and knife switches and protection devices for 250 A are installed in the line part. In the panel there are also installed current transformers and measuring devices.
Panels of the dispatcher control over street lighting
Panel is completed with equipment of control, electricity accounting and protection of street lighting lines against overloads and short circuit currents.
It is recommended to install this panel the last in the row of the distribution device and connect it to the nearest line panel.
This panel is designed for side covering of the distribution board.
For the accounting of electricity (active and reactive), the electricity accounting panel with mounted accounting devices and a glow lamp for warming in a cold season is designed. There is an inspection window (windows) in the case of the panel for taking the readings. Accounting panel is to be mounted on the wall of the electric room.