1. GCK, GCS, MNS are low-voltage withdrawable switchgear.
GGD, GDH, PGL are low-voltage fixed switchgear; XZW integrated distribution box; ZBW box-type substation;
XL, GXL low-voltage distribution cabinet, construction site box; JXF electrical control Box; PZ20, PZ30 series terminal lighting distribution box; PZ40, XDD (R) meter measurement box.
2.the function of low-voltage power switchgear
1) It is convenient to configure the power supply reasonably.
(2) When the line fails, it is beneficial to control the scope of the fault and it is convenient to quickly find the fault point and eliminate it in time.
(3) It is convenient to arrange circuit inspection and repair in pieces, without large-scale power outage.
(4) Various protection devices such as fuses to prevent short circuits and air switches to prevent overload can be conveniently placed in the power distribution cabinet.
3. the composition of the low-voltage power switchgear
(1) The power distribution cabinet mainly includes:
wiring terminals, various switches, protection equipment (air switches, fuses, etc.), measuring equipment (voltmeter, ammeter, cycle meter, etc.), measuring equipment (active and reactive power) .
(2) There are many types of low-voltage power switchgear, and the components are very different. Taking the power cabinet as an example, from top to bottom: knife switch, current transformer, air switch, and branch circuit breakers. If you directly control the electrical load, there are contactors, thermal relays, and branch current transformers under the branch circuit breakers. Of course, there are ammeters, voltmeters, voltage conversion switches, and indicator lights.
4. the content of each digit of the power switchgear model
GGD low-voltage power distribution cabinet: G–low-voltage power distribution cabinet; G–fixed installation and wiring; D–power cabinet;
GCK low-voltage power distribution cabinet: G–cabinet structure; C–drawable type; K–control center;
GCS low-voltage power distribution cabinet: G–enclosed switch cabinet; C–withdrawable type; S–Senyuan electrical system;
MNS low-voltage power distribution cabinet: It is a product manufactured in accordance with the transfer technology of ABB company.
5, the difference between GGD, GCS, GCK, MNS power switchgear
GGD is different from the other three in that it is a fixed type, while GCK, GCS, and MNS are all drawer type switchgear. Each outlet unit of them is independent and each circuit will not affect each other.
GCK is a very old type in China. The profile used at that time was weak and the operating mechanism was not very flexible.
Most of the products now produced have absorbed the advantages of GCS switchgear. It is obviously different from GCS and MNS in that its main bus is placed on the top of the switchgear.
GCS is a new generation of drawer type switch cabinet designed by Senyuan Company in the mid-90s with reference to ABB’s MNS cabinet type.
The main structure is similar to MNS, with the main bus bar behind. The difference from MNS is that the drawer module uses the domestic commonly used 20mm module (MNS is 25mm); the drawer adopts a push mechanism, which makes the operation more convenient and flexible.
The MNS switchgear can be operated on both sides, and a single cabinet can hold 36 loops (with 1/4 drawers) at most, while the GCS can be up to 22. The material used in the MNS cabinet is aluminum-zinc plated, fully assembled structure, no post-processing (galvanizing) is required.
The horizontal busbars of MNS and GCS are separated from the front left drawer unit and the front right cable outlet room with partitions. Their vertical busbars are assembled in flame-retardant plastic functional panels to be more reliable.
The difference is that GCS can only have 1/2 drawer at least, MNS has 1/4 drawer, MNS drawer has another interlocking mechanism, and GCS only has the switch itself.
The difference of GCK is: the horizontal bus is traditionally set on the top of the cabinet, and the vertical bus has no flame-retardant plastic functional board. The cable outlet can be rear-out or can be made into the right-side cable room outlet, but the drawer push mechanism and GCS, MNS is different and simpler.
6. the use of GGD, GCS, GCK, MNS switchgear
(1) GGD Fixed switchgear
GGD is a fixed switchgear, and the fixed cabinet does not say modulus (only drawer cabinets or fixed partition cabinets are represented by modulus, which will be discussed later). GGD AC low-voltage switchgear has reasonable structure, convenient installation and maintenance, good protection performance, and disconnection The advantages of high capacity, but the disadvantage is that there are few loops, the units cannot be combined arbitrarily, the area is large, and the computer cannot be connected.
(2) Chest of drawers
GCK, GCS, and MNS are all drawer switchgear. When it comes to drawer switchgear, we must first understand a concept, that is, modulus E, modulus E= has two values, one is 20mm and the other is 25mm. At present, drawer cabinets are generally processed with two types of profiles, one is KS profile, which has E=20mm; the other is C profile, E=25mm.
Because the cabinet height is 2200mm, the effective height of the drawer (that is, the height of the drawer) is 1800mm, so the GCK of these two profiles can be equipped with 9 drawers, because 8E (E=20) = 160, 8E (E=25 When) = 200 are less than the effective height of 1800.
Take E=25 as an example…
8E/4=200/4 (meaning that 4 drawers are arranged in a 200-high space, with a width of 150)
8E/2=200/2 (meaning that two drawers are arranged in a 200-height space with a width of 300)
8E=Drawer height is 200 and width is 600
12E=The height of the drawer is 300 and the width is 600
16E=Drawer height is 400, width is 600
20E=Drawer height is 500 and width is 600
24E = drawer height is 600 width is 600
1) GCK switchgear
GCK switchgear size:
Width: 400/600/800/1000/1200mm
Depth: 800/1000mm
Height: 2200/2300mm
But one thing to note is that when the rated current of the main busbar is 6300A, the main busbar system is a double-layer busbar system, the cabinet height is 2300mm, and the remaining cabinet heights are 2200mm.
When the rated current of the main bus is 5000A and below, the GCK complete set of equipment can accommodate functional units with an effective height of 72E (E=25mm), and a maximum of 9 layers and 1 unit (8E) outgoing circuits can be arranged. When the rated current of the main busbar is 6300A, the GCK complete set of equipment can accommodate functional units with an effective height of 64E (E=25mm), that is, a maximum of 8 layers and 1 unit outgoing circuits can be arranged. The functional units of the same cabinet can all be installed in drawers or fixed, or mixed. The functional unit room takes 6E or 8E as the minimum height modulus.
When 6E is the minimum height modulus, 12 functional unit drawers can be assembled under the installation height of 72E.
When 8E is the minimum height modulus, 9 functional unit drawers can be assembled under the installation height of 72E. The standard circuit design of the drawer unit has 9 specification levels: 8E/4, 6E/2, 8E/2, 6E, 8E, 12E, 16E, 20E, 24E.
The standard circuit design of the fixed partition unit has 4 specification levels: 6E, 8E, 16E, 24E.
There are three types of propulsion mechanisms for the drawer loop: XJG8 (H1) hand-operated propulsion mechanism, XSL hand-operated propulsion mechanism, and XJG8 (H2) hand-operated electric operation dedicated propulsion mechanism.
2) MNS switchgear
MNS system frame adopts C-shaped frame, standard modulus E=25mm; MNS cabinet dimensions (height x width x depth) 2200mmx400/600/800/1000/1200mmx600/800/1000mm drawer assembly standard specifications are 8E/4, 8E /2, 4E, 6E, 8E, 12E, 16E, 20E, 24E.
Note: 4 8E/4 or 2 8E/2 modules can be installed horizontally in a 600-wide device compartment, and the module height is 8E (200mm). However, 4E, 6E, 8E, 12E, 16E, 20E, 24E single module A 600mm wide device compartment is required, and the height of the module is the size required by the module specifications.
3) GCS switchgear
The frame of GCS is assembled by KS profile with E=20mm;
GCS cabinet dimensions (height x width x depth) 2200mmx400/600/800/1000/1200mmx/800/1000mm drawer unit height modulus is 160mm, divided into 1/2 unit, 1 unit, 1.5 unit, 2 unit, 3 Unit five size series.
In fact, no matter what kind of cabinet is used, the conventional design is considered to be beautiful and convenient to install. It is impossible to completely fill a cabinet. When choosing a fixed partition plug-in switch cabinet for low-voltage switchgear, you can roughly refer to the following:
Circuit breaker: frame air circuit breaker should be used for switches with a capacity of 1000A and above, and plastic case circuit breakers should be used for 800A and below.
Low-voltage output switch cabinet: The height of the low-voltage power distribution cabinet is generally 2.2 meters, and the effective height for placing circuit breakers is 1.8 meters.
The height of circuit breakers with different capacities is as follows:
① Molded case circuit breaker below 250A: 200mm, occupying 8E space, which is the space of a drawer;
② 400A, 630A molded case circuit breaker: 400mm, occupying 16E, which is two drawer space;
③ 800A molded case circuit breaker: 600mm, occupies 24E, which is three drawer space;
④ Number of molded case circuit breakers installed in low-voltage switchgear (reference):
⑤ For 800A molded case circuit breakers, 3 can be installed in 1 cabinet;
⑥ For 400A, 630A molded case circuit breakers, 4 can be installed in one cabinet;
⑦ For molded case circuit breakers of 250A and below, 9 can be installed in one cabinet.