Bigger coolant pump breaker?

[extanker59]

Back in 2008 I asked about our coolant pump breaker. Every couple of days it would kick it out when starting the pump. It was infrequent enough to ignore but lately it's been a few times every day. It's a 10 amp 230 volt breaker.

Geof thought that Haas increased the breaker size so call them. Well, I finally did today. The parts guy said he could only sell me what came on the machine and he didn't have anything bigger to fit. He said he'd email the factory to see if there were any solutions.

Has anyone put a bigger breaker in? Do you have any part numbers and source?

Thanks
Chris

[underthetire]

If it's blowing on start up, I would think the breaker is just too fast. 10 amp on a coolant pump is huge, most pumps are in the 3-6 amp range. I would look in to a slower breaker, or a manual motor starter type. Is it a contactor mounted type or separate ? Have you checked to make sure all three legs are tight with no loose connections? What does the pump tag say for amps ?

http://www.grainger.com/Grainger/SCH...Y89?Pid=search

We typically use this type after the contactor, they are made for longer startup loads.

[Al_The_Man]

Is there any way you can choke down the output slightly to decrease the pump load, Without affecting coolant flow?
If input and output are too wide open, the load on the pump may be the cause.
Al.

[extanker59]

Thanks for the answers guys. We will check the wires after lunch.
The breaker we were looking for had to fit in the existing plug (we think). The pump tag says 5.1-5.3 at the lower voltage.
Restricting coolant is something I'm reluctant about doing but will if no other solutions are found.
Thanks again
Chris

[behindpropeller]

What coolant pump?

I have read that breakers go bad over time.

[Wizzard of H]

The circuit breakers used for those coolant pumps are a type called "magnetic trip". They do not change or go bad over time. The pump motor runs at about 5 amps and starts at about 9 amps. The 10 amp breaker is sized for this and is also designed to run with short-time overloads such as starting a motor. What is described below is almost certainly a motor problem. Check the motor.

[HelicopterJohn]

Hi Chris,

What brand of motor does your unit have?

I had an Baldor 3/4 HP motor on my late year 2007 HAAS TM-1P. It would occasionally trip the 10 AMP breaker. Also, the motor ran hotter than a 2 dollar pistol. You could not hold your hand on the motor. HAAS replaced mine under warranty and supplied a different brand motor. It has ran cool ever since and has never tripped the breaker again.

John

[extanker59]

We have a A.O.Smith 3/4 hp motor. It runs cool to the touch. When it trips the breaker, it just hums without flowing coolant, then trips the breaker.

Our HFO parts guy said he would contact California for info on a bigger breaker. He did. He called yesterday (just an hour after we talked) and had a part number for a 15 amp breaker. Good work.

It's considerably cheaper than a new pump but, because the pump doesn't turn when it kicks the breaker, we are unsure if it will help.

We also shut the machine down and found a few semi loose wires.

We will run it today and see if it kicks the breaker out again.

[Al_The_Man]

Thats a different matter if the pump is not turning it is naturally going to trip the breaker, usually can only be two reasons, something is high friction on the pump from bearings to blockage, the other if the pump is single phasing if a three phase pump, or is start capacitor if 1 phase type.
If any of the above, the larger breaker is not going to solve it.
Al.

[haastec]

It has been a few years, but check the start capacitors for the pump motor. If memory serves correct, I had a couple machines tripping the breaker like you described and I replaced the capacitors. Also, there is simple circuit board that I had to replace on one also; I got that from a local place that distributes and services the Baldor motor. Not sure if the A.O. Smith would have the same, but definitely check and/or replace the capacitors. That shoud be a relatively cheap troubleshoot.

A word of caution about upgrading the pump breaker; if it has been working fine with the smaller breaker and now it does not, that tells me the circuit is overloading and the breaker is doing its job of protecting the machine. Increasing the breaker size just increases the potential for fire. Just something to consider is all. Good luck!

[extanker59]

Yeah, we're leaning away from replacing the breaker. After tightening up the wires, its been quieter when starting and hasn't kicked the breaker out- yet.

How do you go about checking the capacitors? I at least know where they are and what they do but checking them is outside my experience.

[Al_The_Man]

There are ways, but a simple test is with a meter on OHMs range but it is rather crude and not exact.
If it has a centrifugal start winding switch, which if it has two capacitors may confirm this, they sometimes show open and this will cause the same symptoms, usually if you suspect the capacitor, is to just replace them (essential if this is a R.O.C. made motor!), make sure they are AC rated.
Al.