Hey HVAC guys,
My parents have a heat pump, electric furnace set up, and the repairman told my dad, during a routine maintenence check, that the motor should be oiled frequently. On my unit the motor has two tubes that come up, real thin tubing, and these tubes are where you put the oil, and then it flows down to the motor bearings. Is there a special tool that will let you put oil into these tiny tubes, if not any suggestions on oiling? What weight oil should I use. We have tried everything, small tubing will fit over the tubes but then how to get the oil into the small tubing? Any help would be appreciated.
C
Replies
C,
1. Ask the repairman for a bottle of oil.
2. Go to his shop and ask for a bottle.
3. Go to Sears and ask for a bottle of appliance oil.
Etc...
It comes in this bottle that has a pull-out long, thin tube spout. The bottle of oil only costs about 3 dollars. This tube will fit inside those small tubes you are talking about. Fill the metal tubes until the oil is at the top. Run the motor. The oil level should go down in the tubes. Refill the tubes to the top. Do this once every 4 months or so.
There are a lot of electric motors out there on appliances and tools of all sorts that do not have the little metal tubes. Instead, they have just a couple holes where the tubes would be. Sometimes those holes have plastic plugs in them.
If it has the plugs, remove the plugs. then oil it by sticking that long thin 'spout' from the plastic bottle, right in the hole. When there is only the hole, you CAN just fill the hole with oil and then have to oil it again soon. Or, you can run the motor while you are oiling it. More oil will be worked in as you are oiling it, and you will have to come back to it less often.
I have been getting conflicting advice on this one. A serviceman once told me not to over oil, couple of drops every six months for continuous service. Then the instruction on the motor says a teaspoon every six months. I wonder if it is possible for the motor to consume a teaspoon every six months. What do I do?
Tom
"A serviceman once told me not to over oil"
Where is the logic there ?
A few reasons I can think of for this advice...
1. Using the wrong oil. It is possible for some oils to gum up. To thicken. Especialy in a continuous run situation, with the constant heat and friction. If you put too much of the wrong oil in there you could find yourself with a mess and bearings that aren't lubruicated besides.
If you use the right oil for the job, it will never gum up. Bathing the bearings in new oil of the right kind, (too often), is ONLY good for the bearings. There is no bad done to the bearings, only good.
But if you use the wrong oil, it doesn't matter whether you use too much or too little, you are still using the wrong oil.
2. Too much oil, in certain motors, could lead to the oil getting into the works of the motor itself. Oil can be a pretty good conductor of electricity. But this is a situation that will happen with what ? One motor out of several million ? The real bottom line here is that in this situation, you are using an inferior motor. The wrong motor. Get a differet motor.
3. Dust getting into the oil and making slush. A gritty slush that does not do anything good for the bearings. Common sense, man... Use the friggen plastic plugs. Keep the dirt, dust and sawdust OUT of there. This is not a too much oil problem, this is a too much dust, and not enough attention problem.
Take a handfull of bearings. Put them between some metal plates, and start grinding the heck out of them. Do this in two identical setups. Now, oil the bearings in one setup the way that your 'conservative' repairman wants them oiled. And oil the other set constantly. WAAAY too much oil. I wonder which set of bearings is going to wear out the fastest ?
It was reason number 2 that he was concerned about. As I understand the bearing in a blower fan motor is not the sealed type so if there is too much oil, it oozes out around the bearing and dust will settle on it. Then it leads to reason 3. Now, may be the bearings are sealed so putting as much oil in as the reservoir can take and replace the plastic cap would be the best practice.
Tom
Edited 7/11/2002 12:44:44 AM ET by TOMCHARK
Edited 7/11/2002 1:01:19 AM ET by TOMCHARK
These tend to be older motors as most newer, within 25 years, motors have sealed bearings. Many of these motors without sealed bearing have a small label, always small, usually on the side of the motor you can't see and upside down 80% of the time, that tells you what type and how much to use how often. 3 to 5 drops per 3 to 6 months seems to be the range I see most often.
A flashlight, mechanics extension mirror, magnifier and a talent for reading backwards and up side down all help. Advanced yoga classes may be called for. Be sure to kill the power before getting into position. Have someone write down the inscription as you read it out to them. If you can't find a tag call the furnace manufacturer for this information. Most of the larger brands have 1-800 numbers.
"Zoom spout machine oil" is pretty much standard. Specs usually read something on the lines of "non-detergent light machine oil" Zoom spout also comes with an extendable semi-stiff tube about 8" long for tight locations. This oil is usually available at a HVAC or motor supply house. Johnstone Supply is popular with the trades for this sort of stuff. They also carry an extensive selection of motors in case the motor needs replacing.
Don't exceed the recommended amounts. These bearing use very little oil with most of the oil being metered to the bearing from a small felt sponge. Adding more than enough exceeds the felt pads holding capacity and will cause the bearing to leak into the motor housing. These motors typically have vented windings that are indirectly exposed to the air flow. Any excess oil in the motor housing will attract dust that is likely to block the flow of the cooling air or damage the windings directly by attacking the lacquer insulation. Follow the recommendations issued by the manufacturer. They know the holding capacity of the pads and are motivated, contrary to popular belief, to provide a long lasting product.
While your in there vacuum up any dust you find. Particularly around the motor vents. Inspecting, adjusting or replacing the belt, if any, would be good to do at this time also. Given the likely age of the system a newer motor may give you better performance and reliability. That said many of these old motors will last for 60+ years if kept clean and oiled regularly in the recommended amounts. I have been told that more of these motors are killed by over oiling than under oiling. More is not always better.
Edited 7/11/2002 12:42:56 AM ET by 4LORN1
So 4, are you saying that the newer sealed bearing motor doesn't need any oiling? That's what I understand about sealed bearings, they are sealed and you can't get any more oil in. The motor I was talking about was a GE made 2 speed, purchased 2 years ago. under the caps there are channels feeding into the bearings. The label says 1 teaspoon every 6 months for continuous service. I figured one teaspoon is about 60-70 drops.
Tom
ZOOM-SPOUT !!! That's it !!! That's the one I was thinking of.
Thank you.
And youse guys make some pretty good points.
I still prefer to put in plenty of oil, and just keep the area as clean as possible.
I still think that to kill a motor by over-oiling it, you have to have been doing something that went way beyond common sense. And/or simply not doing regular maintenance along with the oiling. If you are paying attention, doing the common maintenance, and cleaning up whenever you oil, I would think that you would spot the problems before they became real problems.
The appropriate oil is made by Bell & Gosset (B & G) and should be available in trade supply houses. The confusion here (several posters) might be between electric motor bearing oil (sparingly, a drop or two every couple of months - don't over-oil) and, for hydronic systems, a teaspoon or so in the circulator pump (not the motor) every couple of months.
T. Jeffery Clarke
Quidvis Recte Factum Quamvis Humile Praeclarum
Edited 7/11/2002 12:15:54 AM ET by Jeff Clarke
Sounds like you belong to the not to over-oil camp. Have you changed your mind after reading Luka's comment? The one teaspoon instruction was on a blower fan motor, not a hydronic system pump. So what's the verdict?
Tom
I was told to use 3-in-1 Electric Motor Oil for the GE motor in our Amana furnace. It's 40-weight. It comes in a can that has a spout that matches the tubes on the motor.
Phill Giles
The Unionville Woodwright
Unionville, Ontario
At the Sears appliance repair center the repair tech told me to "Never, never use 3-in-1 brand oil because it is prone to building up laquer-like resin over time and ruin the motor."
Maybe 3-in-1 makes a motor specific oil that avoids that, but just to be safe I threw away the can of 3-in-1 that I owned and bought a can of 'Zoom Spout' (designed for use in motors).
I guess that the point to this is to read the can carefully and be sure that it is made to be used in an electric motor, and ideally use the oil your motor manufacturer recommends!
I can't speak for the 3in1 multi-purpose oil; but, the 3in1 Electric Motor Oil is specifically made for electric motors (the "Electric Motor" in its name is a tip-off) and I'll trust the motor supplier on this.
.
Phill Giles
The Unionville Woodwright
Unionville, Ontario
Edited 7/11/2002 9:58:05 PM ET by Phill Giles
Not the 3-in-1 general purpose. I use the 3-in-1 SAE20 oil designed for "electric motors 1/4 hp and up", it says on the can.
Tom