- RS232: the software for the chiller rs232 has not yet been written. There is a
program //phenix14/mvdonl/vme/chil.c which is taken from the Greenspring quickstart pamphlet
but it does not work.
Working software for this module is at an Epics site, a tip I got from Lars
Ewell: look for 'Octal
Serial Driver'.
Somewhere there is the code we want.
- How to tune the cooling system safety sensors:
- turn on the fan
- with the anemometers inserted into the circuit, tune the fan speed
such that the flow reads (approximately) 13.4 m/s in the plenum line and 3.1 in the main
volume line. The balance between the two lines is regulated by the big
throttle valve near the fan unit.
- turn on the dehumidification chiller (#2,4), and set it's operating
temperature to 1°C (as low as possible without freezing). You should
see the relative humidity falling.
- turn on the main chiller (#1,3), setpoint 6°C. Let it run for a
while, and watch the temperatures in the air and liquid circuits fall.
See the cooling schematic
and the monitoring
software
- Turn on the power to the MVD; the temperatures should rise a bit, and
then stabilize again.
- First we'll set the temperature trip points on the TxFx sensors in
the air loop, located at the cold air supply near the fan units and below the
MVD in the air cooling lines. Insert the 14-pin test board into the readout
line. Turn trimpot 4 counterclockwise till pin 10 goes high. Measure
the voltage on setpoint 4, and raise the voltage on that point by xx mV,
thereby setting the trip point 5° higher than the current temperature
at that point.
Turn the other pots to trip at different temperatures, by setting
them 5, 10 and 15° below setpoint 4.
- Next the flow sensors: same procedure as for the temperatures: using
trimpot 1 and testing pin 13, find the current rip point, and then go
down so the voltage on test point 1 goes down by 20%. After setting
the flow sensor trip point, it is easy to test by turning the fan off.
Set the second setpoint xxxx.
- Next the liquid flow sensors near the MVD. Same procedure as for the
temperature setting of the air circuit.
- Finally the liquid flow sensors: on the back of the flow sensor is a
small setscrew behind a small hole, and an LED. With the liquid
running, turn the setscrew until the light comes on, and leave it
there. The light should go off when the liquid flow stops.
- exercise the system by using the relay program to force the pump and
fan to stop, and monitoring for example the motherboard voltages.
Last update 7 July 2000 - HvH
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