[evlatests] Antenna 13 Status - Update

[Jim Jackson]

The 48V supply was replaced but unfortunately it appears the equipment up 
in the vertex room is not working. Either the breaker was actually on and 
tripped, or some damage happened earlier.   Rob says that most or all of 
the 48V fuses are blown in the racks and they didn't have enough on hand to 
replace them.  It is also now possible that the P301 and P302 power 
supplies and the inverter in the MCB rack are damaged but we won't know 
that until we power them up.  The DTS modules have reverse polarity 
protection diodes and the remaining modules are transformer isolated from 
the 48 volts by the Vicor regulators. It is unlikely any damage occurred 
beyond the power supplies but at this point, we'll need to test everything.

I will be going out with Rob tomorrow to try to help sort things out. 
Hopefully we won't have to cannibalize Antenna 18 for parts. In a nutshell 
- assume antenna 13 is down until further notice and it should not be 
considered turned over to operations until we recheck everything and rerun 
the acceptance tests.

Jim


At 02:54 PM 3/29/2006, Jim Jackson wrote:
>Rob just called from the site and asked me to send this out.
>
>They just found out the hard way what was wrong with the battery backup in 
>Antenna 13. They repaired the blown fuse, powered it back up and were 
>greeted by sparks, smoke and popping sounds.  Apparently when the main 
>-48V supply was replaced last week, the cables from the batteries to the 
>power supply chassis were accidentally reversed. Being the first antenna, 
>this one had different color wires than the others which apparently led to 
>the confusion.  The power supply chassis and all four rectifier plug-ins 
>are severely damaged and must be replaced.  They are replacing it all now 
>with Antenna 24's power supply and will try to have it running this 
>afternoon - be advised however,  it may take until tomorrow.
>
>The load breaker feeding the electronics upstairs was luckily off at the 
>time so it should have prevented any damage to the electronics in the 
>Vertex room.
>
>Jim
>
>
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