Yet another holman howden compressor thread

Kilroy2k1

New User
Hi
This forum seems to have more info on these compressors then any other place on the net so I had to join to kick in a question or two.

A few months ago I bought a Compair Holman 185 compressor so I can sandblast the 70's Bobcat I am restoring. I've got a separator on order but found out the previous owner bypassed one of the safety cutouts on the unit that actuates the fuel cutoff on the engine.
There are 2 plugged ports in the area where it appears this safety was removed, I put a gauge in the upper port that looks like it was most recently disturbed and it is running at full output pressure so it would definitely trip the fuel cutout actuator.
Any idea if I am on the right port and there is a legitimate problem or if i just have the wrong port?

Compair has been less then helpful, its taken them 3 weeks just to give me the separator part number and just tell me the unit is too old and they likely do not have any books on it.
 
Unless you are getting oil out of the hose you do not need a seperator. Thinking it needs changing due to age, etc is a common misconception. Thing is most people mistakenly view it as a filter and think it's going to get dirty, etc,etc. However, it isn't a filter, it's simply an air maze designed to slow the air down, resulting in the entained oil dropping out. As long as air goes through it, and no oil is exiting the hose, it needs no attention. That said, even if there is some oil escaping, make sure the pickup tube that draws the oil from the seperator isn't kinked, clogged, etc or that will cause oil to build up and pass out with the air.

That said if you have the old one out already and decide tp put it back in insure one thing. That is there needs to be a couple of staples through both of the gaskets on the seperator element. The factory ones are usually heavy stapels and penetrate though the gaskets as wel as the flange. The main thing is that there is a definate metal to metal contact from the metal of the element to the metal of the seperator chamber. Without that contact for static electricity cause by the air flow to pass through a chance of fire exists within the seperator chamber caused by a static spark in what is essencially an flammible, vapor filled atmosphere. I've seen one old IR Gyroflow burned like this and it makes a real mess....




As far as the missing sensor, are you sure it's a pressure sensor and not a temp sensor? I ask because I work on alot of rotary screw, and vane compressors (ie IR Gyroflow vane types, Sullair, Atlas Copco, Gardner Denver, and IR rotary screw types)that range in age from around a few years old to more than 60 years old. Between all of them I have yet to run into one with a pressure sensor on the safety shutdown curcuit. The majority have a normally open low oil pressure switch on the engine that's bypassed by a 'bypass' switch when starting to allow oil prssure to rise and close it for normal operation. The other switches are normally closed and open when a fault occurs. They are usually on the engine water temp (set at 210 degrees rising) and in the oil/air flow on the compressor discharge side (usually set at 250 degrees, rising, on the ones I've seen). I really don't know why there would be a port with any type of pressure sensor in it designed to shut down the engine as I have never seen one with anything like that.

That said if it is a temp switch your needing take a look at Davidson Sales site. I've bought numerous NASON pressure and temp switches from them over the years for the compressors, and other machines, I've worked on. Often times the OEM switches were NASON and simply had the label removed so they could sell them for twice the price....

Good luck and I hope this helps. If you have any more questions or problems feel free ask.
Davidson Sales
 
Thanks for the reply.
Just a little background I should have added in my post. I was a compressor tech for 8 years till i left the industry 15 years ago so I do have a little experience with these. :)
I should also have added the numbers from the air end. It is a Compair Holman 1265 4918 and it run with the Ford 4cyl 2711E diesel engine.

The separator definitely needs changing, the unit was obviously overheated once or twice in its life span and has a few cooked spots on it. the staples are intact and I will assure the replacement has them as well.

The fuel cutout I refer to is a mechanical cutout, plumbed from one of the ports on the air end discharge housing to a small hydraulic cylinder that would push the fuel shutoff lever to 'off' when pressure is applied to the line.

The 1/4" tubing from the hydraulic cylinder is still in place and ends right at the discharge housing where the port I mentioned is.
On the side of the discharge housing there are 2 ports plugged with pipe plugs, one right above the other. Its those ports I need information on.
I put a gauge in the port that looks like it was recently tinkered with and get full discharge pressure on the port, but to be honest both plugs look new with fairly clean teflon tape on them so I may have the wrong port.

It is possible the port had a sacrificial thermal pellet in it and it was melted on the last overheat or there is some form of thermostatic mech that is missing/broken.
I have no problem tearing into this unit but it sure would be nice to know what is supposed to be in there before i do.

I have inspected the rest of the unit, checked the condition of the rotors and even stethoscope'd the bearings and for the age it is in surprisingly good condition, I just need to sort out the safety cutout and it'll be ready to work again.

Thanks
Tom.
 
Sounds like your in one of those prediciments I find my self in on many occasions where the answers coming from the factory are essentially that, 'the man who knows what your asking died a few years back', or something to that effect. I used to have a pretty good go to guy for the Compair stuff but as far as I know he just got out of the business/retired about 8 years ago and I haven't found a replacement. As for myself allof the old books I've got are for the brands I mentioned before, and unfortunately none of them are from Compair. Ultimatly I will keep my eyes open for you, and see what I can find out as the whole deal has gotten me curious, espeically after you posted the additional information.
 

That is exactly where i am at. All the older fellas who know these machines are no longer reachable and Compnnalert is of little help on it. so I appreciate any info you do come across.

There was a gent who helped out the other guy with his Holman unit named circus, I'm not sure if he is still an active member or not and was hoping he would chime in as well. I just cant seem to bring myself to leave him a pm uninvited so I'll keep my fingers crossed.. lol

If it turns out to be a thermostatic issue then I already have a plan of action if necessary to add a thermal switch and solenoid with a latching relay to replace the existing but again I would need the thermal limits to get the proper switch spec.

Thanks again.
Tom
 

And as I typed that... lol

Circus, yes please I would appreciate a copy of anything your willing to share. I can paypal you something for your troubles if you wish.

Tom.
 

I keep saying the same to my friends, "I wish I could win the lottery one of these days, and someday I might even buy a ticket" :)

Thank you very much, you can email me at Kilroy2k1 AT Gmail Dot Com
 
Email and attachments didn't go through. Send me a personal message and I'll try again. Dial up sucks.
 

I tried to send a PM on here and i just get this message,
Private messaging is currently under construction
 
Look at the lower right corner of this posting. You'll see a "Send Email". Hit it. In your message type your Email address so I can send directly to you. My message will be large and have attachment( pages from manual)
 

It might be because i am new on here but I dont see the 'Send Mail' link on any posts, i even tried using classic view and it had [reply] [no email] at the bottom right.
I did unhide my email in my profile settings, dont know if that will help.
 

Thanks to circus who sent me the docs to a similar unit I'm 99% sure it was a thermal pellet that melted when the previous owner overheated the unit. The thermal saved the unit from any damage but confused the owner enough to sell it fairly cheap. :D
I'll hunt up the parts to create an electrical equivalent of the thermal safety and the unit will be up to snuff for my little job.

Thanks circus and NCWayne for your assistance.
Cheers.
Tom.
 
The literature was about 10 years later than my compressor too. 10 years of idiot proofing for this idiot to overcome. The basics were unchanged.
 
Glad to hear Circus was able to help and you figured it out. Got to admit it really had me curious, but a thermal element in that setup really does make sense.
 
These compressors normally whine. It"s the straight cut gears that ups the screws rpm. Don"t worry if it sounds like it"s about to blow up. It"s been frightening me for over 25 years.
 

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