MCH-6 Coltri

A quick note on using oversized circuit breakers, you'll lose all overload protection for your compressor if it should malfunction. If the compressor malfunctions and something is causing it to draw to much current and your breaker size is too large, you'll likely burn the compressor completely up whereas, if you had the correct sized breaker in, there's a strong chance the breaker would trip before letting your compressor get fried.





very true. No different than running too small a wire for a breakers size, and running it too long in length.

The wiring starts to melt and meanwhile your compressors still plugging along, then a major short which fries equipment, starts fires, etc.

Not to mention a big Ka- BOOM! Coming out of your electrical panel


 
I'm new to pcps and air rifles in general (not counting inexpensive pump ups as a kid) and I appreciate reading all the valuable info here. While I don't know pcps that well, I've been around/involved in electrical for a little over 25 years. Did field work for 17+ years and been doing electrical design, quality control and training for engineering firms since leaving the field. I'm currently saving up to pick up an Alkin compressor and I know that I'd likely cry if it was to malfunction and completely burn up due to oversized protection. Based on the spec's for your compressor and distance you plan on it being from the source (electrical panel) I'd be fine running it on #12 thhn wire connected to a 20A/2 pole breaker. If you have a pretty solid service at your house, the in-rush at startup won't affect the 20A breaker. In-rush for motor startup probably doesn't even last for 1 second and definitely not more than 2 seconds. If you were worried about the #12 wire for distance, you could bump it up to #10 to account for voltage drop for distance from the panel. Regardless which size wire you use, I wouldn't go any higher than a 25A/2 pole breaker.
 
  • Like
Reactions: wyshadow
A quick note on using oversized circuit breakers, you'll lose all overload protection for your compressor if it should malfunction. If the compressor malfunctions and something is causing it to draw to much current and your breaker size is too large, you'll likely burn the compressor completely up whereas, if you had the correct sized breaker in, there's a strong chance the breaker would trip before letting your compressor get fried.

A dedicated circuit of the minimum current rating can protect the equipment. Typically, the breaker protects the wiring to the outlet from overload. The best way to protect the equipment, is for it to have it's own built-in breaker of the appropriate rating. That is more common for 110v equipment (my 110v Vevor compressor had one) since it often shares a circuit with other equipment/appliances.

If you are worried about that, and the equipment does not have built in protection, and the outlet that you want to use is greater than 20amps, you can use an adapter cord with built-in breaker rated for 20amp.

https://www.homedepot.com/p/AC-WORKS-1-5-ft-30-Amp-3-Prong-6-30P-Commercial-HVAC-Plug-to-6-15-20-Outlet-with-20-Amp-Breaker-S630CB620/312641282


 
ChadM12,

I just wanted to thank you for your help on this subject. I know Airgun Advisor and I learned something new on this, and I'm sure this will help future air gunners who will try to run wire to power their 220v compressor(s). I first ran the 220v line thinking I would never run anything except my welder but didn't know I could potentially burn out both my compressors on this circuit. I have been running my shop compressor on this circuit for the past 6 years without any mishaps but I'm sure I would have run into trouble as the shop compressor gets older. The amount of money I spent on my Coltri, I want to protect it. This is one of many great things about AGN. Other air gunners helping/protecting other air gunners without knowing the other person. 
 
...snip... I'd likely cry if it was to malfunction and completely burn up due to oversized protection...snip...

I agree with everything you've said so please do not take this response as criticism -- I believe, if you open the control box, there is a sacrificial shunt resistor placed across the start and run capacitor on the motor for the purpose of overload or motor stall handling.
 
...snip... I'd likely cry if it was to malfunction and completely burn up due to oversized protection...snip...

I agree with everything you've said so please do not take this response as criticism -- I believe, if you open the control box, there is a sacrificial shunt resistor placed across the start and run capacitor on the motor for the purpose of overload or motor stall handling.


Would this be what you are talking about?: My Coltri has what looks like they could be thermal fuses on both legs of both capacitors.

IMG_2609.1600369814.JPG

 
I don't think so, those look like electrical blade 4x4 connectors? I think the plastic connectors on the wires is PETE and the plastic on the connector is HDPE?Sorry if I am wrong.

There (I think) should be a electrolytic capacitor across the motor leg that is plate rated. It, at least on mine, has a shunt resistor should the capacitor burn out. It then itself burns out during overload and disconnects the ability for the motor to spin because it severs the circuit. This way there is no way to burn up the motor during a voltage sizing/amperage sizing/breaker sizing/load sizing event.

Sacrifical resistors are used in many appliances. It's almost like engineers actually engineer things to last but then the accountants get involved lol :)
 
I don't think so, those look like electrical blade 4x4 connectors? I think the plastic connectors on the wires is PETE and the plastic on the connector is HDPE?Sorry if I am wrong.

There (I think) should be a electrolytic capacitor across the motor leg that is plate rated. It, at least on mine, has a shunt resistor should the capacitor burn out. It then itself burns out during overload and disconnects the ability for the motor to spin because it severs the circuit. This way there is no way to burn up the motor during a voltage sizing/amperage sizing/breaker sizing/load sizing event.

Sacrifical resistors are used in many appliances. It's almost like engineers actually engineer things to last but then the accountants get involved lol :)

Hello LMNOP, no criticism taken at all. I believe what you're referring to is what is typically called thermal overload protection and I agree with you, it provides the protection you're discussing but without me being able to see a wiring diagram for that particular motor, I don't like to guess. There's a lot of motors that don't come with thermal overload protection and you really don't want to only rely on it for motor protection.

A quick note on using oversized circuit breakers, you'll lose all overload protection for your compressor if it should malfunction. If the compressor malfunctions and something is causing it to draw to much current and your breaker size is too large, you'll likely burn the compressor completely up whereas, if you had the correct sized breaker in, there's a strong chance the breaker would trip before letting your compressor get fried.

A dedicated circuit of the minimum current rating can protect the equipment. Typically, the breaker protects the wiring to the outlet from overload. The best way to protect the equipment, is for it to have it's own built-in breaker of the appropriate rating. That is more common for 110v equipment (my 110v Vevor compressor had one) since it often shares a circuit with other equipment/appliances.

If you are worried about that, and the equipment does not have built in protection, and the outlet that you want to use is greater than 20amps, you can use an adapter cord with built-in breaker rated for 20amp.

https://www.homedepot.com/p/AC-WORKS-1-5-ft-30-Amp-3-Prong-6-30P-Commercial-HVAC-Plug-to-6-15-20-Outlet-with-20-Amp-Breaker-S630CB620/312641282


Hello Scotchmo, the breaker is designed to protect both wire and equipment at the same time. The cord w/breaker protection you mentioned would just trip the breaker a little sooner as it's closer to the motor but if your electrical system is correctly wired, the time difference would be negligible.
 
...The cord w/breaker protection you mentioned would just trip the breaker a little sooner as it's closer to the motor but if your electrical system is correctly wired, the time difference would be negligible.

A LOT sooner.

The cord with the built in 20amp breaker will trip under load conditions that will have no affect on the 30amp breaker servicing the outlet that the cord is plugged into.
 
I just got my first High end compressor. It sure was heavy. I need to order the plug for it. 

After using the Yong Heng for over a year, I decided to go with a more faster fill compressor without the need of external cooling.

After many research , My first choice was the MCH-6 but then I learnt about the Alkin W31 Mariner Vertical Compressor from

AGN forum. So I decided the Alkin W31 Mariner Vertical model will be my choice. It uses lower RPM so that mean less heats.

The box arrived damaged from the back but when I open the box the compressor doesn't has any damage.

Got me nervous for a minute. It does put a dent in my saving account. I kept it a secret from

my wife. 😅 But I'm sure happy to get it in. Can't wait to put it to work. 





Alkin 5.1601708229.jpg
Alkin 6.1601708229.jpg


Alkin 1.1601708244.jpg
Alkin 2.1601708245.jpg
Alkin 3.1601708245.jpg
Alkin 4.1601708245.jpg



 
I just got my first High end compressor. It sure was heavy. I need to order the plug for it. 

After using the Yong Heng for over a year, I decided to go with a more faster fill compressor without the need of external cooling.

After many research , My first choice was the MCH-6 but then I learnt about the Alkin W31 Mariner Vertical Compressor from

AGN forum. So I decided the Alkin W31 Mariner Vertical model will be my choice. It uses lower RPM so that mean less heats.

The box arrived damaged from the back but when I open the box the compressor doesn't has any damage.

Got me nervous for a minute. It does put a dent in my saving account. I kept it a secret from

my wife. 😅 But I'm sure happy to get it in. Can't wait to put it to work. 





Alkin 5.1601708229.jpg
Alkin 6.1601708229.jpg


Alkin 1.1601708244.jpg
Alkin 2.1601708245.jpg
Alkin 3.1601708245.jpg
Alkin 4.1601708245.jpg


Congrats on that awesome unit..air for ever!👊..👍


 
... It uses lower RPM so that mean less heats...


The amount of heat is not determined by design RPM. Heat is a function of the volume rate and pressure of the air being compressed. The Alkin appears to have a bigger fan and that would be a requirement since it is turning at a lower RPM than the Coltri.

A bigger fan that is turning slower, can cool the same as a smaller fan that is turning faster. Same heat dissapation.
 

... It uses lower RPM so that mean less heats...


The amount of heat is not determined by design RPM. Heat is a function of the volume rate and pressure of the air being compressed. The Alkin appears to have a bigger fan and that would be a requirement since it is turning at a lower RPM than the Coltri.

A bigger fan that is turning slower, can cool the same as a smaller fan that is turning faster. Same heat dissapation.

Thanks for the information. 😊
 
Update pictures of what I had done for the wiring. I had my electrician come in to run wire and this what he did:

He hard wired the shop compressor directly to the one breaker and then ran another outlet off the same break just incase I need to use my arc welder.

Resized_20201003_212517.1601782943.jpeg


One breaker is for the compressor and the other is for the Coltri

Resized_20201003_212607.1601782964.jpeg


From the breaker, he ran wire into the existing conduit and then adding another outlet for the Coltri

Resized_20201003_212624.1601782989.jpeg


I think he did a great job. I would never have thought to hardwire the shop compressor in and I would have ran another conduit to my work bench. Very clean job. Now I can rest assure all my equipment will be safe.
 
For those asking about wiring size/gauge, according to the specs the load on the single phase model is 17 amps @ 230 volts. Different ways of figuring this but most residential electrical services are 120/240V. If you take 17A x 230V = 3,910 watts. Voltage goes up / amperage goes down so 3,910 watts divided by 240V = 16.3 amps. They are including in-rush of the motor at startup to achieve the 17A they claim. In-rush is short lived but can strain a motor a bit if being used on a heavily loaded circuit. Specs state 3hp / 2.2 kW, 2.2kW = 2.2 x 1,000 = 2,200 watts. 2,200 watts divided by 240V = 9.2 amps. 9.2A would be the assumed "full run load" for the compressor motor. In a residential setting, this unit would likely work just fine on 15A, 2-pole breaker with 14 gauge wire as long as the circuit is not heavily loaded. 20A, 2-pole breaker and 12 gauge wire will have no issues at all. A little extra information for those who might need it in the future, almost all standard distribution breakers, both commercially and residentially under 200A are designed to trip the breaker once they exceed 80% load of the stated breaker size, regardless of poles (1, 2 or 3). 20A breaker will trip if continuous load exceeds 16A (this does not count in-rush at startup for motors), 15A breaker will trip if continuous load exceeds 12A, 30A breaker will trip if continuous load exceeds 24A, so on and so forth. All that being said, if you're worried about your wiring, bump up one size in wire. Regarding the OP's original comment about the wire running deep into the motor, if it's factory wiring, I would leave it be as it was designed and built utilizing components and sizing they know to work as they want it to. Also, typically, internal motor wiring or cord wiring is totally different in spec than your standard household wiring. Hope this helps. Sorry it's so long! 



Chad! This kind of info is awesome. I can tell you know your stuff. Just wanted to say thank you for posting this. I get everything you laid down.


 
It's a good question @Harv24. All wire attached to a 30 amp circuit should be 10 ga. or larger. Wire attached to a 20 amp circuit must be at least 12 gauge, 15 amp takes 14 gauge. So the wire attached from your breaker to the outlet is likely 10-2 with a ground or 10-3 with a ground depending on the outlet. The challenge now comes in the wiring to the compressor and the compressor itself. If the power cord is 12 gauge, then it can't handle 30 amps, meaning the it could start melting and short before the breaker tripped; or the motor wiring shorting.

I think that unit pulls 14+ amps, but I could totally be wrong on that. Check the manual. When it heats up and the bottle is on the high end of compression it'll pull more. If that's the case, I personally would consider a 20 amp breaker. My 120V version can trip a 20A breaker if I'm running it long and hard topping off bottles.

Your mileage may vary, and it's just my thoughts on the matter. You could monitor the amperage and make a more informed decision.
 
sideplate.1642514806.jpg


My Alkin W31 horizontal compressor has a 4HP factory motor that has a 15.6 amp rating on the side plate. It is wired into a 220V circuit that has a 30 amp breaker in the electrical panel. A friend of mine checked the wiring under load using an amp meter. The amp draw was 14 amps after startup, peak was 16.5 amps at full pressure. The motor has a 1.35 safety factor which means it can handle a peak of 21 amps so it's running within the normal limits. The voltage reading is 243. The outlet has 10 gauge wire to a Nema 5-20 type plug receptacle.