Intelliflo VSF 011056 running on undersized wiring and 15A breaker

[AMGolf]

I've gotten lots of good info from this site over the years, and have had many questions answered. Some, however, I've answered for myself, and now will be posting a series of topical guides to things I've figured out that other folks may find useful.

I just did a complete overhaul of my pool pad, replacing a very old Anthony bronze 1.5hp pump and VA-52-2 DE filter with new gear. I wanted the Intelliflo VSF 011056 pump. One issue that arose is that my current wiring is a 140ft run of 14ga conductors, coming off a Double Pole 15a breaker. This will not support the Intelliflo at full potential output. Further, voltage drop at that distance is a major concern. 8a is about all I can draw at that distance without losing more than 3% voltage (house voltage starts at 237v). However, 6a x 230v is more wattage than I need to maintain flow rates of 75GPM in my 2" plumbing.

Because you can limit the max RPM, and because 2" plumbing introduces enough restriction anyway to limit flow and therefore wattage, running the Intelliflo here works fine. I made a video showing in real time the voltage drop at various RPM and flow rates.

Here, also, is a table of my starting GPM/PSI for a fairly clean filter. (a dirty filter increases restriction and therefore reduces flow and wattage at a given RPM).

3100RPM; 77GPM, 26PSI at pump; 1726w; 14PSI at filter
2700RPM; 68GPM, 20PSI at pump; 1168w; 10PSI at filter
1700RPM; 40GPM, 7PSI at pump; 305w; 1.5PSI at filter
1100RPM; 24GPM, 3PSI at pump; 91w; 0PSI at filter

Hope someone finds that useful.

 

[ajw22]

Not recommended but you made it work.

If it does not work the 15A CB will trip.

 

[Darin]

You are just gonna have to figure out what is the max speed at the highest pressure and lock out all speeds above that. Example is the VFD i run i can limit hz which them limits how many watts my motor will draw. I wouldn't be too concerned about the plumbing size or the 140' as that is not really far. Besides you have the fluke to tell you how many amps you are drawing.

 

[AMGolf]

Not recommended but you made it work.

If it does not work the 15A CB will trip.

I was more concerned at a point of undervoltage damaging the motor. If I succeeded in drawing a steady 15a, I'd drop at least 6% in voltage but would be cranking out 3.3kw of work. If this was a single speed pump, that would be grossly oversized for my pool's plumbing based on other recommendations here.

I'd never built it this way to start, and am exploring running a subpanel to the garage, and then another sub to the pool which would fully solve all this. I wrestled with doing that vs what pump to buy, but in knowing that this pump ramps up (vs slamming on with huge inrush current), and knowing you can limit output to match need, I went ahead and bought it and set about exploring what actually happens to voltage at the end of that long run.

Based on my findings, running a subpanel isn't such a pressing need.

For those interested, I also have a gas heater, SWCG, and blower. There's a second 14ga, 15a, 240v circuit that was previously just for the blower. For now, that circuit powers Relays 1 (SWCG & heater) and 2 (blower). Relay #1 is also the pump relay, so when iAqualink/Z4 calls for the pump to come on, it energizes this relay. The pump itself is wired directly to its own circuit, but is controlled by the iAqualink as well via RS-485. When I do rewire things, the new 20a circuit will power the pump, SWCG, and heater as is ideal.

 

[Darin]

theoretically you are getting 12 amps at 141'. 6 amps on each 120 volt leg (#14)

According to your data above 1726 watts at 223 V = 7.7 amps total. This works, just don't put anything else on the circuit.

 

[ajw22]

The Intelliflo pump should have adequate under voltage protection to shut itself down and not allow damage. It has error messages for Under Voltage shutdown.

 

[Darin]

ajw22 is correct they are dc motors with smart controllers. Anyway at that distance the line loss is minimal.

 

[AMGolf]

Good to know about Under Voltage shutdown. I'd be curious to know what the level is, or if running it just above that threshold for years could cause premature failure (or the normal operating voltage range in general)?

 

[Darin]

your controller should be able to handle anything from 215 - 245 volts pretty easy. An example is the Vgreen which says 230V +10% -7%, so anywhere from 214V-253V