Dave's ESL Cafe's Student Discussion Forums

[rice07]

Hi

...


The electricity grid supplying Africa's biggest economy came close to collapse in January, forcing the government to declare a national emergency. Gold and platinum mines were forced to shut down for five days.

Since then mines have been operating below full power, driving up precious metal prices and raising fears of possible job losses and slowed growth.

The company would declare force majeure if it is unable to meet supply contract obligations.

Etzinger said nine generators had tripped, and another nine were down for planned maintenance. South Africa has about 160 generators.

...

The above is an excerpt from newspaper titled 'S Africa's Eskom may cut mines' power'. My questions are the bold parts as follows.

1. had tripped=> Does it mean 'had started functioning'?

2. another nine were down for planned maintenance=> Does it mean 'another nine generators were not working for planned maintenance'?

Much obliged!
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[pugachevV]

Every generator has a safety system that will shut it down in case of overload, short circuit, or some other emergency that might damage the equipment if allowed to continue.
In electrical circuits, this often takes the form of a circuit breaker, the function of which is, as its name suggests, to break or interrupt the circuit. When this happens the circuit breaker is said to have "tripped".

Naturally, this means that the generator is out of service until the fault that shut it down is attended to.

When equipment is down for maintenance, it means that it is out of service while maintenance is performed on it. This might include replacing worn parts, lubrication and so on.

[rice07]

Hi PugachevV

But for your explicit elaboration, it would not be that clear to me.

Now I learned it. I can never thank you enough!