In the last days, some test was performed on the motor of the WE F#0 vertical hoist ("chioccolone"), with the aim to measure the motor heating under running conditions.

Motor and mounting described in elog #33290.

This motor is quite particular with respect to the other ones installed on each SA, because it has to move  a large load (about 1 ton) and because the duration of the movement can last up to tens of hours.

Therefore, it is important to check the thermal behaviour of the motor when running with the usage of the new motor driver. 

To perform this measurement:

-  a temperature sensor (a 3-wire PT100)  was attached on the motor body;

- the chiocciolone was installed in its final position inside the Filter #0

- the Filter #0 was loaded with a dummy load equivalent to the nominal weight (around 1 ton).

In the first  run  the old motor driver was used, performing 600000 steps (400 steps to perform one  motor revolution, speed equals to 1 rev every 16 seconds);

In the second  run  the new motor driver was used, performing 900000 steps (200 steps to perform one  motor revolution, speed equals to 1 rev every 16 seconds,  current set at 2A/phase via SW by G.Ballardin),

The attached  fig show the comparison between the temperature behaviour during the two runs:

- the 1st plot is the T sensor on the motor body, the 2nd plot is a T sensor on one end of the crossbar (ie about 0.5m far from the motor),

-black curves denote the 1st run, purple curves denote the 2nd run (the noise on the purple curve, 1st plot is due to an elecrtical  contact problem)

A few considerations:

- with the new driver, the steady state temperature is 65C, instead with the old one is not higher than 40C.  --> ie the heating produced by the new driver is at least twice the old one.

- the test was performed in air, so once under real conditions (ie in vacuum), the T increase is expected to be higher.

Further investigation will follow.