Installing booster fan via relay switch from Microwave fan wiring

[KeepItSimpleStupid]

Another choice: Buy another fan. https://www.encompassparts.com/item/8172159/Samsung/DE31-00028N/Motor_Ac_Ventilation Do what you need to do to the new part.

i.e. cut neutral. Add a single contact plug. Male/female. Then add a length of wire with plugs on both ends that wraps on the sensor.

Your mods are on the fan side. To restore "like new", install the blower that came with the microwave.

Save the original part for when the microwave needs service.

 

[MisterMateo]

Hmm, good ideas KISS.
Had not considered a second fan. That's very do-able.

The pin connection on the fan has no markings. However the two blue clips on the back of the connector each have a marking, one as "KET 1" and the other "KET 3".
There are 6 total connection points or pins. These six are about 12 cm X 12 cm together.
I looked for them on the web yesterday without any luck. I'll try again with some of the names you suggested.

Thanks again. I really appreciate your time.

 

[MisterMateo]

Found the connector online, but its a Korean company and not available online, from what I can see, unless you are a big purchaser.
**broken link removed**

(made by Korea Electric Terminal)

Looks like I may be back to the drawing board. Wondering if any US connector suppliers may have access to KET products.

 

[killivolt]

They do make an in duct fan for just this purpose. **broken link removed**

kv

 

[MisterMateo]

Killivolt,
You are correct. Actually purchased this first, as it was what gave me the idea when I was putting together my system. However I have decided to spend the money and upgrade to a better self contained fan made by fan tech. I purchased model FG6M.

The Suncourt customer reviews online were poor - I checked reviews on several sites. It's main complaint was noise and durability. The Fantech reviews were very positive and is the real deal in my opinion.

I'll be able see soon enough as the fan is on its way and should have it installed soon.

Thanks for your response, I appreciate it.

 

[KeepItSimpleStupid]

The drawing board is still the buy a replacement fan which isn't a bad option. You just extend the neutral wire with a 1 pin connector so you can wrap it around the sensor. I'd also wrap the sensor with some Kapton tape. It can withstand 200 C easy and remove with no residue.

==

The other part of the process involves connecting the sensor to "the wall" Take a look here https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CCwQFjAC&url=https://www.dalroad.co.uk/wp-content/uploads/2014/06/ampsealedconnectors.pdf&ei=qdlpVZrbOMHRsAXkwoPQDQ&usg=AFQjCNG8Zt_pzLZEnQxGlW_ejZyzJo2Shg starting on PDF page 32. Look through series 11.

Somewhat thinking of the corrogated tube over fiberglass sleaving over Teflon insulated wire. I'll be first to admit overkill, but I can't see any issues with that construction.

I don't think you need sealed connectors, but the corrugated backshells should fit the non-sealed versions.

The unsealed size 11 right angle adapters will extend about 2" (guessing) and that may be a bit much. Digikey has the unsealed versions.

Mouser.com had the right angle backshells for at least one of the the corrogated versions. I didn't quite have the time to compute the clearance needed for the smaller version and estimated the series one version. Nor do I know how much clearance you have to mount a right angle backshell/connector.

These connectors (unsealed anyway) are easy to work with.

==

Dimensions and clearances get to to be a pain.

==

The next issue is to be able mount the magnecraft relay which I think is a good choice. It's finger safe and a small 40 VA energy limited transformer in some sort of "flush mounted" box. All wiring in the box should be rated for 300 V and the connector COULD go on it's lid. It doesn't have to because it's rated at 24 VAC. You could put a freehanging version in a pocket.

A NEMA rated enclosure with a clear lid might make everyone happy. e.g. https://www.polycase.com/ml-series Mount it in a recess.

Remember I'm just bouncing ideas.

 

[KeepItSimpleStupid]

The BC2G here http://www.hammondmfg.com/ba.htm would work and so would this: http://www.alliedelec.com/1/product...-engry-lmt-transformer-mfr-part-90-t40m1.html

Without physical separation, the insulation resistance of the wires has to be of the highest voltage in the box. You'd want to keep them separated if you can.

 

[KeepItSimpleStupid]

Since we're brainstorming, another idea is a reflective object sensor on the blower. e.g. **broken link removed**

or https://www.nextwarehouse.com/item/?1935307_g10e or whatever.

A piece of reflective tape would be placed on the blower. Electronics configured as a frequency switch or a missing pulse detector does the switching.
Drawbacks, sure. Sensor could get dirty.

A tiny Neodymium magnet (really tiny) and a hall effect sensor could be used too. I'm going to far in left field, but it's OK. It's not meant to be the answer.

 

[KeepItSimpleStupid]

You need significantly less than 40 VA 24 VAC, but that's a common value used in HVAC systems. Some HVAC systems fuse the secondary wit a 3A automotive blade fuse and the transformers may or may not be energy limiting.

 

[KeepItSimpleStupid]

A clarification: Mounting of a flanged enclosure

You may have the option of grating a recess up to about 15" wide and a fair amount of height,
You could mount the flanged base on anything from a piece of angle to a bent piece of thin aluminum if you need the extra space. First, though, the components have to fit in the box.

Being visible and neat, it's likely to pass. A UL rating for the parts (xformer and relay) and a NEMA rating for the box and your mostly ready to go.

 

[KeepItSimpleStupid]

A cheaper AC switch: https://www.dwyer-inst.com/Product/ProcessControl/CurrentTransformers-Switches/SeriesMCS/Ordering

 

[MisterMateo]

This last AC switch link you provided is not 24V, correct? Looks like 130 V DC/AC

 

[KeepItSimpleStupid]

130 AC/DC 0.3 A is the contact rating maximum. It can switch AC or DC to 130 V, BUT it has an output rating of only 300 mA which is likely not enough to run the booster fan directly. So, it could switch 12 VDC, 24 VDC, 24 VAC and 120 VAC and others.

The spec sheet neglects to say whether or not the measured current is DC, AC or both. Hall effect sensors can do both. Current transformer technology AC. The low current version has no hole. It does say INPUT AC in the picture, but not in the spec sheet. Ive used stuff manufactured by Dwyer (Air velocity measurement systems and alarms)

It still COULD be a viable option.