I’m using a Blue Smart Fan switch to control a Panasonic FV-30VQ3 ventilation fan. Unlike many other popular Panasonic fans, this model has an AC motor. The VZM35SN has neutral connected.
This arrangement “works”, but it isn’t to my liking:
When the fan is on High, it’s quite loud. It rattles too. I think this is partly because there is a 6" → 5" reducer in the duct, until I can get around to enlarging the hole in my roof.
When the fan is on Medium, it’s almost silent. It doesn’t move a lot of air and I would prefer that it run faster. Maybe somewhere around 75% of the High airflow.
When the fan is on Low, it’s imperceptibly quiet. It runs very very slowly and this setting is useless to me due to the minimal airflow.
So I’d like Low to run about the same speed as the present Medium, and I’d like for Medium to run about halfway between the present Medium and the present High.
I do not want to change High (although I won’t use it unless I really need max airflow).
Will this require a hardware modification in order to replace capacitors with different values? If so, can anyone share what they did and what the results were like?
I’m comfortable working with 120V electronics and I have repaired several fried Insteon switches in the past.
It would require capacitor changes. I haven’t seen anyone changing them here. Put the medium speed size in for the low and one half that for the medium and see what happens.
Are there any reasons not to try this? I’ll probably need to buy a spare VZM35 to experiment on, since I don’t want my setup to be out of service for extended periods of time.
Are these PCBs relatively easy to work on without destroying the unit? Do we have any pics showing the caps, and/or specs for what is in there now?
For comparison: in a non-Inovelli canopy module from Home Depot, I see that there are two enormous yellow capacitors next to two relays. When I change the fan speed on this module I can hear the relays clicking. I’m guessing that only one capacitor is active at a time and the relays switch them to be in series with the load. Does the VZM35 operate in a similar manner?
I have ordered a second unit to experiment on. Will leave the original installed in the wall for now, and tear apart the new one on the lab bench.
@EricM_Inovelli is there any information you could provide to help with this? A snippet of the schematic and part numbers for those capacitors would be useful, since that would let me order a couple of replacement parts with similar specs/sizes but different capacitance values.
I can check with the engineers about the capacitors. I have a defective unit as well that I can look for any markings on. They are crammed together so I’ll have to cut them out. FYI High speed can’t be changed because it doesn’t go through the capacitors and is just full 120VAC to the fan.
Thanks for checking. Do you know how these values were chosen, or if there are any constraints on replacing them?
8.7uF does seem unusually large for a fan speed controller, which maybe explains the poor performance on Low speed.
Part numbers, if available, are potentially useful in that it would allow for ordering a replacement in a similar physical size but with just a different capacitance.
Otherwise I was thinking to order a few ~1uF-2uF “audiophiler” MKP caps off ebay that looked like they might fit. They’re advertised for use with speaker crossovers but most are rated up to 250V.
How much higher than 8.7uF would I need to go, then? If I chose e.g. 100uF would it be close to full speed or would it still be noticeably slower?
It would really help to understand how Inovelli chose the original values. I could just order a whole bunch of caps off eBay and solder them into the circuit one by one, but that’s a slow and frustrating process.
I’m super interested in this topic as I have 5x Hunter fans exhibiting the same “ultra slow, slow, max” speeds while controlled through the VZM35SN. It almost made me want to return them since mainly the middle speed is all I want to use now.
I opened up one of the original Hunter fan controllers and found 2x 5uF, 1x 0.33uF. Any recommendation about how to select capacitors that are compatible with the VZM35SN? These are physically quite large and I want to make sure anything I buy to experiment with is compatible.
Out of curiosity, you set the ceiling fan’s pull chain to high, right? Or is there no pull chain if the fan came with a remote? I’m asking because I have a bunch of Hunter AC fans and I’m not seeing that. Although opinions on what the proper speed ought to be at a specific setting will vary.
I bought my fans without remotes so I have the pull chain to vary speed out of the box. Since yours came with remotes that you removed, I’m wondering if there might be some other difference that’s causing an issue here.
There are no pull chain on these. They are 52in 6-blade Hunter AC fans chosen for their E26 replaceable bulbs and their high CFM rating (no home AC ). Each came with their own remote and RF canopy module which have been removed entirely. While I agree that opinions vary on preferred speeds, I have noticed a large difference in the OEM slow speed vs the VZM35SN slow speed, and it looks like there is some difference in capacitance between each controller…
It is mainly the lowest speed through VZM35SN which I would like to modify. I think I may try to experiment by removing the VZM35SN 's existing 8.7uF cap and swapping the existing 4.7uF cap into its PCB location. Then I will experiment by adding something like a 3uF or 2.2uF in the location where the 4.7uF was installed. However, Im a little hesitant to try prior to learning more about specs of the caps used in VZM35 by default
I think the 4.5uF is a starter cap, not involved in speed regulation?
Few minor updates from my end:
I received the new VZM35SN that I’d like to use for experimentation. I was able to disassemble it. Two initial questions: a) it looks like it is necessary to desolder a triac to get access underneath the “capacitor PCB”? and b) does this design include bleeder resistors, so that the big yellow caps won’t store 120V after power is disconnected?
I installed a VZM36 canopy module on a different fan (an old 48" Casablanca). Qualitatively, Inovelli’s Low speed seems slower than Low on the pull chain did. On this fan, though, it’s tolerable.
I wanted to post quantitative current readings for #2, but it looks like the fan modules do not have an ammeter? I’ll measure with a clamp meter when I have the setup taken apart again.
Possibly, larger motors are impacted more than smaller ones? I found this online:
A capacitor has an impedence of 1 / ( 2 * pi * f * c ) ohms.
As a thumb rule, a 1 uF capacitor will offer 3142 ohms (say 3 K) at 50 Hz; a 2.2 uF will be 1.5 K and 3.3 uF 1K.
Since there is no power loss in the capacitor, it will behave like a lossless Resistive regulator.
So, if I’m doing the math right, 8.7uF @ 60 Hz gives us:
1 / (2 * 3.14 * 60 * 0.0000087) = 305.054757 ohms
My guess would be that module uses 1 x 5uF for low and puts both in parallel to make 10uF for medium speed.
The Inovelli likely uses the 4.7uF for low speed and the 8uF for medium speed.
With 2 capacitors you can either use 1 for low, both in parallel for medium, or you could do 1 for low, the other for medium and both in parallel for another faster medium speed.
@EricM_Inovelli - can you confirm how the capacitors are used? If one is for low and the other is for medium then maybe a software update could add another medium speed by turning both capacitors on.
You know, if you switched to possibly something like a 4.7uF and 6.8uF you could have 4 speeds, 4.7uF, 6.8uF, 11.5uF by turning both on at the same time, and then full power bypassing the capacitors.
So I don’t know how these caps are getting switched in/out of the circuit. Would appreciate some guidance from the designers so we can approach this problem in a more strategic way rather than guessing.
). Each came with their own remote and RF canopy module which have been removed entirely. While I agree that opinions vary on preferred speeds, I have noticed a large difference in the OEM slow speed vs the VZM35SN slow speed, and it looks like there is some difference in capacitance between each controller…
