tim5055 Posted January 21, 2014 Report Share Posted January 21, 2014 Well, I'm moving forward on replacing the septic with a connection to the sewer system. This will require the installation of a macerator/injection pump. This pump requires a 220v/20a circuit. Near the location where the plumber wants the electric installed is my sub-panel for our pool equipment. The sub is being supplied by a 60a breaker, but I can't tell what gauge the wire is. Here is the panel with the breaker for the sub marked: In the sub there is a 20a GFCI for the underwater light (20a overkill for a light?) and the 220/20a for the pump Here is the sub: So, can I pull from here or is the wire insufficient for the load? Quote Link to comment Share on other sites More sharing options...
David Meiland Posted January 21, 2014 Report Share Posted January 21, 2014 You raise the question of wire gauge from the 60A breaker, and of course that should be answered. The breaker is there to protect the wire in question. Assuming you have a proper 60A subpanel I see no reason why you can't add another 20A/240 breaker to it and run your ejector. Curious why your ejector is 240. I have a Liberty 350 (I think) and it's 120. Lots of those around here. Quote Link to comment Share on other sites More sharing options...
ghentjr Posted January 21, 2014 Report Share Posted January 21, 2014 The 60 amp breaker wire looks like #8 which should be adequate for your needs. No GFCI for your pool pump? Is the sub panel properly connected to the main panel? Quote Link to comment Share on other sites More sharing options...
tim5055 Posted January 21, 2014 Author Report Share Posted January 21, 2014 Curious why your ejector is 240. I have a Liberty 350 (I think) and it's 120. Lots of those around here. Thanks for the quick reply. I'm just going with the recommendation of the installer on the pump. The house is quite a distance from the sewer main and (forgive me, sewer is not my high point) the system is a "forced main". So, could it be the distance or pressure? Quote Link to comment Share on other sites More sharing options...
Greg Booth Posted January 21, 2014 Report Share Posted January 21, 2014 Curious why your ejector is 240. I have a Liberty 350 (I think) and it's 120. Lots of those around here. Thanks for the quick reply. I'm just going with the recommendation of the installer on the pump. The house is quite a distance from the sewer main and (forgive me, sewer is not my high point) the system is a "forced main". So, could it be the distance or pressure? .........one size does not fit all applications. There is also the distinction between macerators which grind the solids and send to a forced main emptying to the sewer and effluent pumps in septic systems that only move the liquids from the tank to the absorption field Quote Link to comment Share on other sites More sharing options...
kurt Posted January 21, 2014 Report Share Posted January 21, 2014 Yes, not enough info. Don't rely on your plumber for electrical advice. I've always found plumbers to be the least analytically inclined trade. Get some specs for the pump, wiring, and the loads in the rest of the house from an electrician. Better yet, two different electricians. Come back here with the info. Quote Link to comment Share on other sites More sharing options...
Marc Posted January 21, 2014 Report Share Posted January 21, 2014 It looks more like a #6 to me, 60 amp feed. A 20 amp circuit certainly won't over tax it, not even a motorload. Look at the nameplate on the pump motor if you've doubts about the voltage or amps. Like Kurt opined, listen to the plumber and nod nicely, but forget everything he's said about electric once he's done talking. Marc Quote Link to comment Share on other sites More sharing options...
tim5055 Posted January 21, 2014 Author Report Share Posted January 21, 2014 Yes, not enough info. Don't rely on your plumber for electrical advice. I've always found plumbers to be the least analytically inclined trade. Get some specs for the pump, wiring, and the loads in the rest of the house from an electrician. Better yet, two different electricians. Come back here with the info. Nope, never thought to rely on the plumber for electrical advice. It looks more like a #6 to me, 60 amp feed. A 20 amp circuit certainly won't over tax it, not even a motorload. Look at the nameplate on the pump motor if you've doubts about the voltage or amps. Like Kurt opined, listen to the plumber and nod nicely, but forget everything he's said about electric once he's done talking. Marc OK, here is what they are installing: WE1512HH - Goulds Pumps 3885 Submersible Effluent Pump The manufacturer spec sheet shows the following: 1.5HP 1 Phase 208V 3450 RPM Max Amps 15.7 Locked Rotor Amps 50 (what the heck is this?) KVA Code "H" Start Resistance 11.3 Line-Line Resistance 1.6 Power Cable Size 14/3 Quote Link to comment Share on other sites More sharing options...
John Kogel Posted January 21, 2014 Report Share Posted January 21, 2014 Locked rotor amps to me means if she freezes up, the motor could draw up to 50 amps, so be sure to include a 20 amp breaker. Just a warning, IOW. That appears to be a hefty pump, as you say, maybe to overcome the sewer pipe pressure. I'm pleased to hear you are going that route, as it will help to dry out your yard and save the fishys too. Quote Link to comment Share on other sites More sharing options...
tim5055 Posted January 21, 2014 Author Report Share Posted January 21, 2014 Locked rotor amps to me means if she freezes up, the motor could draw up to 50 amps, so be sure to include a 20 amp breaker. Just a warning, IOW. That appears to be a hefty pump, as you say, maybe to overcome the sewer pipe pressure. I'm pleased to hear you are going that route, as it will help to dry out your yard and save the fishys too. I plan on the 20a breaker. As to the plans, my first thought was a straight pipe all the way down to the lake, but I assumed they would figure it out quickly[:-bigeyes No, I want it done right. I sleep better not worrying about things. Quote Link to comment Share on other sites More sharing options...
Marc Posted January 21, 2014 Report Share Posted January 21, 2014 OK, here is what they are installing: WE1512HH - Goulds Pumps 3885 Submersible Effluent Pump The manufacturer spec sheet shows the following: 1.5HP 1 Phase 208V 3450 RPM Max Amps 15.7 Locked Rotor Amps 50 (what the heck is this?) KVA Code "H" Start Resistance 11.3 Line-Line Resistance 1.6 Power Cable Size 14/3 120 volts via a 20 amp thermal-magnetic breaker won't reliably start a 1 1/2 horse motor (won't hold locked rotor amps), hence the higher voltage specification. My engineering pocket book recommends a 30 amp circuit for 1 1/2 HP single phase motor running on 240 volts. It agrees with the #14 wire for the circuit but since this appliance has only one motor, you need to size the wire to the breaker, which is a #10 for a 30 amp breaker. I'm not saying you'll positively have problems with the 20 amp circuit, but you might. Even if the mechanical pump itself only draws 1/2 HP from your 1 1/2 HP rated motor, there's still the need to supply that locked rotor amperage for a couple seconds while the rotor comes up to speed. Your 60 amp panel should handle this pump easily. Is there a 240 volt rating on the nameplate? 208 is available on 3 phase services only. Is that what you have? If the motor is fed with 240 instead of 208, the max load amps goes down a little, making it even easier on your 20 amp circuit but the label should specify 240 as an option on the nameplate if your electric service is a standard 120/240 service. Most motors do. Don't listen to any electrician who says the 240 volt option isn't needed to run a '208 volt only' motor on 240. Unless it's rated for both, you might over-saturate the magnetic core of the motor on the higher voltage, drawing steeply higher amps, even with no load. As John K said, locked rotor is amp draw when the rotor isn't moving for any reason. So that's what the motor draws for an instant when you first switch it on. Locked rotor is usually about double max load amps for capacitor-start single phase motors. Locked rotor rises when you raise the voltage from 208 to 240, but max amps at full load drops instead. Marc Click to Enlarge 54.82 KB Quote Link to comment Share on other sites More sharing options...
tim5055 Posted January 22, 2014 Author Report Share Posted January 22, 2014 Is there a 240 volt rating on the nameplate? OK, when I copied it I shortened it - Oops It actually has 208 and 230 in the same box Quote Link to comment Share on other sites More sharing options...
Marc Posted January 22, 2014 Report Share Posted January 22, 2014 Is there a 240 volt rating on the nameplate? OK, when I copied it I shortened it - Oops It actually has 208 and 230 in the same box Good. It's good for 240 then. Marc Quote Link to comment Share on other sites More sharing options...
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