****** - Verified Buyer
4.5
I needed this switch for my duct fan. It starts up perfectly, but doesn’t shutdown immediately. I think it runs about ten minutes after the AC stops. I’m guessing there is still pressure in the diaphragm??I looked at mounting this switch on the air handler, but there wasn't a really good spot to drill and mount it since the fan is at the far end. So I mounted it on the side of the plenum. But you can't just stick screws into a fiberboard plenum and expect it to stay put. So I devised a mounting plate which is a piece of steel stock, where I added a 1in bend on top.I set the stock on the outside of the box with the bend resting on top, and marked where the 2 holes were drilled on the outside so I knew how . I drilled the plenum at the marks (actually pushed a punch thru).Then I made a slice on top of the plenum as shown, and pushed the plate down through the slice until the 1in bend was sitting on top. I then made the port opening send mounted the switch. Then I pushed the metal screws through the plenum, and fished around until they were over the holes. Then I tightened them gently so not to crush the fiberboard.Then I taped the top 1in bend to secure it and prevent leaks. Diagram A shows the location of the switch, and the cut. Diagram B shows the metal stock.This is of course all unnecessary if you have access to the inside of the plenum, when you can add a mount plate and nuts with no trickery.After day 1, I'm very impressed. My UV purifier and my booster fans all are working perfectly. I have 3 zones- the loft, the living room, and the bedroom. At any one time only one zone would normally be on since we usually occupy the same room. But more than one CAN be on. I expect this to produce a savings, since cooling is now biased to the occupied zone. So I can set the thermostat to say 74, but if I'm in the bedroom, most of the airflow will be in there. So the bedroom may get to say 70, before the loft (where the thermostat is) reaches 74. Which is perfect because we're not keeping unoccupied rooms as cool as occupied rooms.My longterm goal once sensors get better, is to set these up as "scenes" oh my home hub, and let it decide which fans need to be on. But unlike lighting, cooling is a much longer-term proposal- I don't want to redirect cooling to the bedroom just because I walk in there to get a pair of glasses. The control switches ARE ZWAVE, so for now, I may just estimate occupancy by time of day. After 11, its a good bed BR is occupied and the other rooms are not.This switch was a vital missing component from the whole A/C control system. I had to know when it was running. Its a little *once-removed* from a *true* test which might be inductive sensors on the fan wires for example, but I'm pretty confident this switch will serve the purpose well.I purchased the Tjernlund PS1503 to activate a Tjernlund M-6 duct fan. The PS1503 instructions include no meaningful wiring instructions. Emailing customer support gave me incorrect information. I finally was able to contact Tom, from Tjernlund (by phone), who walked me through wiring the two units together. See images.You essentially interrupt the black wire from a power source, separating it from the 3 black wire grouping in the fan, running it to the "Common" terminal, then running another wire from the "normal open" terminal back to the fan (nutting to the remainder of the original 3 black wire grouping in the fan). Wire all the grounds together. I used a 2 wire Romex (black, white, bare ground). You could use an extension cord with a ground plug and cut the plugs off.Tom noted that you need to install the PS1503 so the air flow runs directly at the sensor. If that is not possible, he recommended securing a "bendy straw" pointed towards the air flow (his "59 cent" recommendation). Worked like a charm.Don't mount the PS1503 too close to the fan, or it will activate, run briefly, then shut off, then run again continuously alternating being activated and deactivated. I had to separate the PS1503 from the fan by installing it in the attic after a frustrating failure installing it 3-4 feet before the fan. I assume the negative pressure from being too close to the fan caused the on-off-on-off failure.Now that the PS1503 is in the attic, and the M-6 fan is in the crawl space...it works perfectly. Instead of a $15,000 furnace/AC install, I was able to install a duct booster fan, pressure switch, and new ducting for $250. Works perfectly to help heat and cool our basement. It is a reasonably quiet fan.I'd recommend drilling a hole in the M-6 fan's plastic wiring box to add a snap-in connector (wire support bracket). I purchased a 2 pack at Home Depot and added the other connector bracket support to the box of the PS1503 pressure switch (already had an open hole in the wiring box). Solid cord protection. Looks professional.
