**SSD Cooling System**

This document gives a brief description of the SSD air cooling system
and some guidance on how to turn it on and check its status.

PAY ATTENTION, TURNING POWER BREAKERS IS NOW FORBIDDEN FOR UNTRAINED
PERSON.

### The SSD cooling system

The SSD is cooled down by the mean of an air flow induced at one end of
every ladder and sucking the fresh cooled taken from the TPC inner field
cage through the full volume of the ladder. The air flow is produced by
an compressed air running into air flow amplifiers called vortec. The
compressed air is produced by a dedicated compressor located in the
second floor of the STAR assembly building. A schematic drawing of this
system is the following :

The compressed air is produced by a compressor and is going immediately
trough a filter on the second floor of the room at the East side of the
Assembly building. At this level they are 2 manual valves. One is
between the compressor and the filter and one right after the filter.
There is a manual gauge just before the second valve. The air compressed
air is then running trough a copper pipe up the on side of STAR in the
Wide Angle Hall.

![](media/image1.jpeg){width="3.75in" height="5.0in"}

![](media/image2.jpeg){width="4.4222222222222225in"
height="2.527083333333333in"}

![](media/image3.jpeg){width="3.75in" height="5.0in"}

![](media/image4.jpeg){width="3.125in" height="4.166666666666667in"}

From the North-West side the copper pipe is approaching STAR. At this
point, there is an electronic valve and an electronic gauge. After the
gauge, the flexible hose is connected to the copper pipe to serve the
West side of STAR while the copper pipe is running parallel to STAR to
reach the East side. The hoses are connected to manual gauges and valves
that should be open and then to the vortecs.

![](media/image5.jpeg){width="4.411111111111111in"
height="3.316666666666667in"}

### How to turn on the SSD cooling system

**BE AWARE THAT YOU ARE NOT ABLE TO TURN POWER BREAKERS BY YOURSELF
ANYMORE**

This means that step 3 to 5 are forbidden to you. Call Bill Christie or
try to find Bob Soja to do that.

1.  Check that the electronic valve is open. The valve is controlled by
    the SVT slow control. The procedure to control the valve status is
    describe in a file on the ch3linux machine. Check the file
    SSDvalve.help in the directory /home/ssd/Docs. Be careful since
    important SVT hardware is remotely controlled by the same system.

2.  Go to the Assembly building room. Make sure that the two manual
    valves are open. They are usually open (the handle should be
    parallel to the pipe)

3.  Turn on the filter power breaker

4.  Turn on the filter (turn the red button)

5.  Turn on the compressor power breaker

6.  Check the compressor status (a message like "ready to start")

7.  Start the compressor (press the green start button)

8.  Check the compressor status (the pressure should rise and stabilize
    around 120 psi with some oscillations)

### Something is wrong with the cooling system

If the temperature reading and/or the compressed air pressure indicated
on the slow control windows are not normal (typically the pressure equal
to 15 psi) something is wrong with the cooling system.

The first thing to check is the electrovalve status. Its default state
is closed so if something happened to the electrical apparatus
controlling this valve, the valve will close itself.

If the valve is open, then they are good chances that the compressor
itself is in a bad state (the manual valves between the compressor and
the rest of the cooling system are usually open).

1.  Check the compressor status on the small display. If the compressor
    is ok, it should indicate a pressure close to 120 psi. If this is
    not the case, the compressor must be reinitialized.

2.  Try to do a "stop" by pressing the red button near the display. If
    it works, try a "start" and check the message on the display and the
    pressure growing.

3.  If the compressor fault is severe, pressing the "stop" button does
    not help. On must power cycle the compressor. For that, one must
    switch up/down the compressor power breaker. Turn it off, wait a few
    moment and turn it on again.

4.  When the display says something like "ready to start", press the
    green "start" button. The pressure reading should rise on the
    display and on the gauge located after the filter.

5.  If it does not work, do not insist. Ask the Operation group (Ralph
    Brown) to have a look at the compressor. In the mean time, leave the
    SSD completely OFF.