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small metering pump spec

small metering pump spec

small metering pump spec

have a very small metering pump that runs on 120VAC and Current of 1.4A with a max output of 250 PSI. Due to the size, what is a good relay and starter size that it will need irrespective of the distance between power source and point of installation which h gives a negligible VD.Asking cos this is a very small pump..

RE: small metering pump spec

I don't see using a motor starter for that small a motor. It should be internally protected.
I would look at relays in the 10 Amp, 250 Volt range.
Possibly plug-ins with din rail mount sockets.
I would pick a 10 Amp relay within my budget and look at the specs for any reason that it may be unsuitable.

Ohm's law
Not just a good idea;
It's the LAW!

RE: small metering pump spec

yes 10A is too much, may be a 2 A relay will just be sufficient

RE: small metering pump spec

10 Amp relays are plentiful and cheap.


yes 10A is too much, may be a 2 A relay will just be sufficient
Try it and see.
We don't know what type of motor you are using.
The rule of thumb for an induction motor is that starting current is six times running current.
The first cycle transient may more than double that.


Current of 1.4A
1.4A x 6 = 8.4 Amps.
A 2 Amp relay will work just fine, until it doesn't.
(Amazon will sell you 2 10 Amp relays with bases for $12.You may chose to spend a little more for better quality.)

Ohm's law
Not just a good idea;
It's the LAW!

RE: small metering pump spec

Iu are right. Oh me I did not consider max starting current , was just looking at the FLA of 1.4. I think using a factor of 7 for max running current gives me a 9.8A. So yes a 10A relay will be good. Thanks for that update

RE: small metering pump spec

1.4A @ 115VAC puts it at somewhere around 1/10th HP. Most common relays are good for up to 1/2HP. A "motor starter" would be overkill for something this small.

Look at the motor nameplate (if you can), it should tell you if it is self-protected and if so, you do not need external OL protection. It may say "Thermally Protected", it might just have a "TP" on the nameplate, or it might say something like "impedance protected", meaning it is designed to avoid starting a fire even if the motor is stalled indefinitely. A number of small 115V metering pumps I have connected have been impedance protected.

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