Detailed explanation of the layout of three American standard medium voltage armored switchgear
ABB
Advance non arc switchgear, typical American standard switchgear
Advance -15kV and below, 4.76/8.25
Advance- 27 --27kV,
SafeGear arc cabinet with pressure release switch cabinet
SafeGear --50kA
SafeGear HD --63kA
85inch 2159mm deep, 36inch 914mm wide, 95inch 2413mm high; The cabinet adopts the folding and bending technology (double-layer bending) to increase rigidity and safety, and the cabinet adopts a galvanized steel plate assembly structure.
Circuit breakers and functional handcarts are both in the form of chassis vehicles, with door closing and rocking in and out operations. Auxiliary devices such as PT use Delrin arc extinguishing contacts, and the contact box size is small to meet insulation and dynamic thermal stability requirements.

You can choose to deepen the front by 10 inches 254mm for the instrument room, or increase the rear cabinet by 7 inches 178mm.
The pressure relief channels for the lower handcart compartment and busbar compartment are located in the middle of the front cabinet and at the rear of the instrument room. The arc is led to the upper empty compartment to the top of the cabinet through the shared pressure relief channel, and then released to the outside of the switch room through the horizontal pressure relief channel on the top of the cabinet.

Schneider
MasterClad ™ Type switchgear
36 inch wide frame structure, fully metal separated structure between compartments, low voltage instrument/control room isolated from high voltage, grounded metal partition enclosing all live parts, equipped with automatic metal valves, and fully insulated busbar.
Complete mechanical interlocking, pull-out power transformer CPT and voltage transformer VTs, automatic grounding discharge after the handcart is pulled out, and the circuit breaker cart cannot be closed between the testing/disconnection and connection positions.

The upper part of the switchgear that meets the internal arc fault level generally cannot be equipped with a circuit breaker handcart, but an auxiliary function handcart is installed. The depth of the auxiliary function compartment is smaller than that of the circuit breaker compartment, so as to ensure smooth airflow. The internal arc can be released through the rear space of the auxiliary function compartment. The primary contact of the auxiliary function compartment handcart is connected to the main busbar or cable side copper bar through a high-voltage insulated cable.
Siemens' GM-SG and GM-SG AR, 7.2, and 15kV models.
The non arcing switch cabinet GM-SG frame type cabinet structure has no separate instrument room. The anime devices are installed on both sides and the upper part of the compartment in front of the circuit breaker, which is convenient for installation and maintenance.
GM-SG AR anti internal arc fault level switchgear, with a separate metal partition instrument room located in the middle of the front cabinet. There is a pressure relief channel installed at the top.

GM-SG AR anti internal arc fault level switchgear, with a separate metal partition instrument room located in the middle of the front cabinet. There is a pressure relief channel installed at the top.
Auxiliary function handcart switch cabinet
The four compartments from top to bottom, as shown in the diagram on the lower left side from top to bottom, are as follows:
2-Bus side voltage transformer, 4-Bus side power transformer, 2-Bus side voltage transformer, 6-Bus side power transformer fuse, power transformer installed behind the cabinet.

It is also possible to install voltage transformers and high-voltage fuses for the entire height of the handcart.
Traditional American standard medium voltage switchgear, non arcing type, with double-layer circuit breakers arranged on top and bottom, no separate instrument room, and highly integrated high-voltage and protection control circuits for each outgoing circuit, easy to inspect and maintain, and reliable.

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