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Lola Maroun

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Aug 2, 2024, 10:43:47 PM8/2/24

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If you sort a global label table into any order other than the unsorted order that appears by default you are unable to create, delete or edit any labels. Our Mitsubishi representative discovered that if you click on the column header between 'Data Type' and 'Class' the order does not change but now editing is available. This, it turns out is a really bad idea. It seems the position the label was in when it was created is preserved, I think this is the unsorted order you get by default. If you sort the list and then delete a label it is possible that the label that should be in that position is also deleted.

I have attached a small project to demonstrate this. Open the Global Labels notice the order they were created. Now change the sort order, click on the column header I described earlier to make them editable and then delete the label in position 1.

For a while I thought this was the only problem but recently there has been a number of instances where I have created a label, given it a carefully selected address only to discover that it is being overwritten by another variable. I have not been able to work out exactly what is going on but I believe it is connected to the sort order of the labels. Also if you sort the order and change an address, have you changed the address of another label? The only solution I have found is to keep label tables very short so they are managable without having to sort the order, that is probably good practice anyway

I have been using a number of axes in pairs, in incremental mode as caterpillar feeders, using FX5U-40SSC simple motion modules. I had a problem that the axis synchronised to follow would suddenly stop moving, the customer was having to power down the machine and start again. This problem persisted for months with Mitsubishi scratching their heads unable to fathom it out and ultimately stating that the problem must be in my code somewhere. It was suggested by the customer that it may be getting to a software limit, I showed the customer that the software limit was disabled in the setup and it was confirmed by Mitsubishi that it was not the problem. guess what, it is a problem.

Once the actual position reached the limit of the double word memory it would stop moving. The solution is the take the servos out of synchronisation in order to set the position (datum) to zero every cycle. Unfortunately the drives do not always re-synch on the first attempt so you have to keep trying till it does, this now causes slight variations in cycle times but it works.

EDIT: I have since been informed that to disable the software limits they must be set to zero. This implies that the Enable/Disable setting is invalid and the limits are defaulted to their respective max values. Surely a default to zero would be more appropriate.

Dry mode works by reducing the airflow and keeping the inside coil really cold. The idea is rather than cool a lot of air a little, you cool a little air a lot, which condenses out more moisture, since you air dropping the air significantly below the ambient dew point.

If the temp is dropping, but the humidity is staying the same (%rh), you actually are dehumidifying since your dew point is dropping, and there are fewer pounds of water in the air. The thing to remember about relative humidity is... that it's relative (to temperature). So it's possible to dry the air and increase the rh simultaneously.

If it's cool outside (say less than 50f), you may be able to "dehumidify" by simply by ventilating more (assuming inside it's kept around 70f). Crack a window or run the bathroom fans. This works even if the rh is high outside, because it's relative to a low temperature, thus a low dew point. The dewpoint can't exceed the temperature, or you simply get condensing since the air is saturated.

It could be that your head(s) is significantly oversized for the conditions that occur in dry mode.
I would suggest only running one head in dry mode, and leaving the other head off completely. Don't run in AC and dry mode at the same time unless you need the sensible cooling effect as well.

I was hoping this would work and get rid of my DH that we have been using. The temp was down to 62 when I cut it off and was getting ready to leave for the week. Not sure how low it would go or if it would cut off if we left it on. I probably really over did my trailer. We really did put two mini splits in each with two heads. Last year our first year there when we got down for the weekend it just took too long to cool it down and after the hurricane took out our ducts I decided to go with mini splits.

Throwing 40,000 BTU/hr of compressor at a sub-18,000 BTU/hr peak load it means all heads will be cycling (UNLESS you put it in DRY mode). The modulation range is not infinite, and unless the compressors are running and the coils are cold it won't be removing any moisture.

Try turning one of them completely off (throw the breaker), and run just one head on the other, so that it has enough load to work with when humidity is the primary load. (Turning off the other head with the remote doesn't turn it completely off- there is still refrigerant running through it whenever the other head is calling for coolth/heat.)