What is the difference between the double power supply and the double circuit of the two stage in the standard?
Now the standard is very chaotic, past the "power supply system design code" GB50052-1995 version will load into a level load, two load and three load; "standard" power supply system design for the GB50052-2009 version will load into critical load, important load and general load; "power users important power users of power supply and power emergency power supply configuration specification" will have the important load is divided into grade, grade one or two important power users and temporary four important power users; you do not know the "two level load" is refers to the outdated "power supply system design specifications" version of the GB50052-1995 two level load!! Notice that it's called heavy load now;
Double power refers to the two lines of two power point, when the problems of a power point, another power point will not affect the normal power supply; and the double loop is two power lines, can be drawn from the same substation, the substation when the problem, may two road can not guarantee the power supply; in a sense, dual power supply must be double loop double loop, but not necessarily double power supply.
So for the important load (note the no level two load statement), should be equipped with "dual power", if the two transformers from a 10kV power supply, from the understanding of rules is not allowed; if the two transformers respectively by two different power line power supply, can be regarded as the dual power supply two lines are drawn, can be as an important load power supply; if two transformers were composed of two 10kV with a power supply substation outlet, then called dual power supply, called double loop power supply in version 95 is allowed, but the 09 version;
For the two stage load, the load can be approximately regarded as an important load, according to the requirements of the GB50052-2009 code for design of power supply and distribution systems:The power supply for important loads shall comply with the following provisions:The power supply of the 1. important load shall be supplied by a double power supply, and the other power supply shall not be damaged at the same time when a power supply fails.2. the power supply of the equipment under the important load shall be one of the following modes of power supply according to the power supply conditions and the importance of the load:1) double power supply, switching in the last stage distribution device.2) the double power supply is supplied to the appropriate distribution point switching device, and then sent to the power equipment or its control device by special line.3) a small capacity load can be switched at the end with either a power supply plus an uninterruptible power supply, or a power supply plus a battery pack with the device itself.
