How should one understand trisomy 21 closure?
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The design drawings will mention things such as: 1. Is there a three-in-two interlock for the main supply’s two 10KV side circuit breakers and the bus coupler switch? 2. Is there a three-in-two interlock for the main switch on the 10KV side of the standby transformer, the main switch on the 10KV side of the generator, and the bus coupler switch? How should we understand trisomy 2 with atrioventricular block?
43 people have already viewed it – why isn’t there anyone expert who can explain it? Regarding the first point, if I run two transformers in parallel, wouldn’t all three switches be closed then? What needs to be locked out? As for the second point, it is understandable: with three switches, only two can be activated at a time. For example, when the backup transformer fails and loses power, and the generator is started, the switch on the transformer side should be turned off to prevent reverse power flow. My understanding is that with three switches and a time element, once interlocking is enabled, the busbar switch can be used for pairing – I’m not sure if that’s correct
It’s a choice between two options: First, paralleling transformers through a loop carries risks; if the situation at the higher level is not clear, the circulating current can be very high. Therefore, it is generally required to close the connection at the higher level first before enabling parallel operation. As a result, automatic switching systems operate by first disconnecting and then reconnecting, in order to prevent accidents caused by circulating currents
It’s a choice between two options: First, paralleling transformers through a loop carries risks; if the situation at the higher level is not clear, the circulating current can be very high. Therefore, it is generally required to close the connection at the higher level first before enabling parallel operation. As a result, automatic switching systems operate by first disconnecting and then reconnecting, in order to prevent accidents caused by circulating currents
As indicated in the drawings from the power design institute, my understanding is that when two transformers operate in parallel, the circuit breakers for the two power supplies should be closed first, followed by closing the busbar switch. If one power supply is closed along with the busbar switch, closing the switch for another power supply will cause power feedback. Therefore, the busbars must be closed together, which leads to the locking phenomenon mentioned above. But I didn’t see the schematic diagram; it was just replaced with a sentence, so it’s not very clear. I just started working on this project, so I called the design institute to ask, and I’m also checking to see if anyone else has come across it
The main purpose is to prevent circulating currents. If the load is of high importance, power may be supplied from different substations; in such cases, the system’s circulating currents can be quite large, and an accident may occur at the moment of switching on
According to your explanation, then transformers cannot operate in parallel? I’ll check again
Whether transformers are operated in parallel is mainly determined by the size of the load; transformers can be operated in parallel
Transformers have been used in parallel operation, but I’m not sure what to do with this addition made by this design institute
Two incoming lines and one bus coupler; these three switches cannot all be closed at the same time, with a maximum of two being closed