F61 Penn flow switch range adjustment at site

[K.R.Iyer]

Need a help:
Penn make F61-TB-9100 model flow switch has a range adjustment screw at the top near the electrical terminals. The adjustment screw is very small size, kept inside a bronze nut or socket.
How do I adjust the setting? Use a wrench on the bronze nut or a mini-screw driver to turn the small screw inside?
I tried both. The spring below seems to move. But want to do it the right way. Has anyone adjusted the setting for this model flow switch at site? What is the right way to do it?
Thanks for your help!

[RANGER1]

Should be easy to turn, big screwdriver slot I think.
Restrict flow to minimum required, then adjust to open circuit flow switch.
Then double check again to be sure.

https://be-ebusiness.eu.johnsoncontrols.com/vb/FileDownloadServlet?filename=85C1E5010AFAE309E89534FAC594C9110D74FED4DF78AAA8F613AEFF0C4B9E88D0EFF82 BD75C1CA1CB069F64058AEDDD33F654390AB8F60910E883B924AF8E1263038AE1A7D047876E55F4CC5F0C2A58EB2B3C150F9 2F6D500B5CED7A62D403600219FC513D65851CD8173BCDADAAE0655140E55BE794B0A

[frank]

I would also determine if the flow rate was correct for the machine before carrying out any adjustments

[Grizzly]

15035
Spot on Frank!
These switches operate at such low flow rates, that the adjustment left is tiny!
The factory minimum flow settings are very low.

If adjustment is due to poor flow then there is very little left to adjust.
Good Luck all the same K.R.Iyer.
Grizzly

[RANGER1]

Sensitivity is also adjusted by number of paddles, how big pipe is, length of paddle, restriction in pipe from paddle.
Attention to paddle getting hung up on something internal.
To me old technology, electronic more adjustable & reliable, little bit more expensive.
If critical & know minimum flow rate, hire a flow meter to calibrate it.

[Grizzly]

Some good and valid points Ranger.
The flow of the medium through the Chiller is so important.
But also in some instances the most ignored.
Most new installs I go to don't even have Binder points to be able to measure the flow
Grizzly

[Tycho]

Need a help:
Penn make F61-TB-9100 model flow switch has a range adjustment screw at the top near the electrical terminals. The adjustment screw is very small size, kept inside a bronze nut or socket.
How do I adjust the setting? Use a wrench on the bronze nut or a mini-screw driver to turn the small screw inside?
I tried both. The spring below seems to move. But want to do it the right way. Has anyone adjusted the setting for this model flow switch at site? What is the right way to do it?
Thanks for your help!

The Penn flow switch is delivered with minimum flow adjusted, this is said in the user manual that comes with the flow switch, as well as in the manual that RANGER1 posted.


HOWEVER, the nut with the tiny screw inside is almost impossible to adjust, and it feels like you are going to break it when you try.

adjusting the spring tension can be done by using an adjustable spanner on the nut, or a tiny screwdriver on the screw inside the nut.

But you have to use a adjustable spanner or a wrench that fits, on the hexagon nut first to really wriggle it loose first, when you have applied enough force to think "Nah... I'm gonna break something" you are using half the force needed.

The Penn F61 is a *piece of something" and it has a reputation as a flow switch, because once you have flow it switches to not working....

I have used all range of stainless steel paddled that come with them , or even replaced the stainless steel paddles with home made paddles made from the soft sides from a plastic oil canister... the only difference is that fitted with the home made paddle, it worked about a month before it started leaking internally and short circuited the entire control panel...

[al]

Same as the johnson control ones, had a few sites where quarterly maintenance the small screw had to be tweaked to get it to go off, i prefer dual pressure ones.

[K.R.Iyer]

Thanks for all the useful insights from all of you! A big benefit of this forum.

In this site I was called upon, the switch was mounted on a manifold and I could not ascertain the flow shape inside (circular or square). It was not responding to higher flow than rating (reference: its rating catalog).
The original switch had only a single paddle, that too slightly bent in flow direction. I replaced it with a new one, increasing its length (compared to old one) and keeping 5 mm gap at bottom. Also added another two small paddles behind the new long paddle, for reinforcement.
it worked now - on increase of flow. Made minor flow setting adjustment as needed by customer, Checked 3 times for cut-off and cut-in. It worked well.
Thanks once again!

[Tycho]

We've stopped using the Penn flow switch and have started using this one, with no moving parts.

https://www.pctflow.com/our-products/flow-meters/thermodynamic/ege-liquid-flow-sensor-sn-450-liquid-flow-controller/

[K.R.Iyer]

We've stopped using the Penn flow switch and have started using this one, with no moving parts.

https://www.pctflow.com/our-products/flow-meters/thermodynamic/ege-liquid-flow-sensor-sn-450-liquid-flow-controller/


Had a look at this product. Thanks!

[RANGER1]

They are a little expensive, but worth it.
You can adjust scaling on some & also see if/when flow drops off.

[Tycho]

They are a little expensive, but worth it.
You can adjust scaling on some & also see if/when flow drops off.

it'll be a one time higher cost, instead of many slightly smaller as the Penn switches die after 3 months :D

We've only used the ones with switches inside, but the also come with 4-20 mA output for flow reading.