Confusing nameplate

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pete m.

Senior Member
Location
Ohio
Hope this works... (attempting to add a picture to this post. If it does work a big thank you to Moderator George)

Found this nameplate on a VAV while doing a rough above ceiling inspection yesterday. I will be following up with the listing agency.

Pete



View attachment 5213
 

david luchini

Moderator
Staff member
Location
Connecticut
Occupation
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According to the Price website, the 1/4HP fan motor at 208V has a 0.8A FLA.

I'd guess the other 28A is electric heat and/or other misc. loads. It looks like for the MCA they are taking 125% of the total load: 1.25x28.8=36.1,

but for the MOP, they are taking 2.5% for the fan motor plus 100% of the rest of the load: 2.5x0.8 + 28 = 30.
 

DetroitEE

Senior Member
Location
Detroit, MI
According to the Price website, the 1/4HP fan motor at 208V has a 0.8A FLA.

I'd guess the other 28A is electric heat and/or other misc. loads. It looks like for the MCA they are taking 125% of the total load: 1.25x28.8=36.1,

but for the MOP, they are taking 2.5% for the fan motor plus 100% of the rest of the load: 2.5x0.8 + 28 = 30.

Good point, there must be an electric heater in there if those ampacities are correct. Though I still don't understand how the MCA could be larger than the MOP.
 

steve66

Senior Member
Location
Illinois
Occupation
Engineer
Looks like an error on the label. The MOCP is obviously wrong if the MCA is right.

IMO, this should be thrown back to the manufacturer to fix the label.

Steve
 

pete m.

Senior Member
Location
Ohio
UL 1995 is for heating and cooling equipment.

My guess is that there are some heating elements present.

Exactly. There are resistance heating elements integral to the unit. The NEC would call it a Duct Heater. I've always heard of them called VAV's which may not be 100% accurate.

I'm currently attempting to explain the issue with the nameplate to the listing agency.

Pete
 
Hope this works... (attempting to add a picture to this post. If it does work a big thank you to Moderator George)

Found this nameplate on a VAV while doing a rough above ceiling inspection yesterday. I will be following up with the listing agency.

Pete



View attachment 5213

So what the nameplate tells us, and others had deciphered the functional assembly, that it is a forced air heater with an integral motor. The motor is thermally protected, so they let you know that the motor overload protection is being taken care of, you only have to worry about short circuit protection as heaters can not 'overload'. What bothers me though that if the motor is stopped because of the motor thermal cutout, the heater can overheat unless there are other instructions in the referenced manual that takes care of the issue. I don't understand though why won't they list the heater wattage, only the motor size. Still insufficent information to say that this is the correct conclusion though....:cool:
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
What bothers me though that if the motor is stopped because of the motor thermal cutout, the heater can overheat unless there are other instructions in the referenced manual that takes care of the issue.

Wouldn't the heaters have a some thermal protection to avoid over heating?
 

steve66

Senior Member
Location
Illinois
Occupation
Engineer
Wouldn't the heaters have a some thermal protection to avoid over heating?

Yes, I'm sure it would contain a thermal fuse or breaker and probably also an air flow switch interlock.

What bothers me though that if the motor is stopped because of the motor thermal cutout, the heater can overheat unless there are other instructions in the referenced manual that takes care of the issue.

I'm not sure why you wouldn't think this is already taken care of inside the unit???
 
Yes, I'm sure it would contain a thermal fuse or breaker and probably also an air flow switch interlock.

I'm not sure why you wouldn't think this is already taken care of inside the unit???

Because you are asking me to assume. We all know what happens when one assusmes.

The OP supplied a nameplate and I limited my comments to the information supplied on it. All the rest is speculative, however good and sound that is, it is not suported by any evidence presented here.
 

steve66

Senior Member
Location
Illinois
Occupation
Engineer
Because you are asking me to assume. We all know what happens when one assusmes.

The OP supplied a nameplate and I limited my comments to the information supplied on it. All the rest is speculative, however good and sound that is, it is not suported by any evidence presented here.

Its a UL listed piece of equipment. The necessary safties would be included, or the instructions would cover the proper installation. No need to assume anything.

Steve
 

steve66

Senior Member
Location
Illinois
Occupation
Engineer
Can you SHOW me any material evidence to your claim that was supplied here? (Not to mention that it is listed by ETL not UL.)


Yes.

[SIZE=-1][SIZE=-1]Automatic reset thermal cut out specifically matched to each unit to protect from overheating in case the minimum air flow requirements are not met.
[/SIZE]
[SIZE=-1]Secondary thermal cutout is in the power circuit and is used as a backup in case of failure of the automatic reset thermal cutout.
[/SIZE]
[SIZE=-1]Recirculating fan is interlocked with the heating elements to ensure that the fan is operational prior to the heating elements being energized.
[/SIZE]
[/SIZE]

http://www.price-hvac.com/catalog/F_all/SectionF.aspx?pageRequest=FPV_1

When you buy a new appliance, do you have to take it apart and analyze every piece to make sure its safe to plug in???? Apparently so, we wouldn't want you to have to "assume" anything.
 

hurk27

Senior Member
About 6 or7 years ago, I helped UL investigate a case on Fedder/Sears inwall electric heat/air units, after several fires were caused by them, I was involved with one home and a guard shack fire.

These units had an electric heating element right behind the out vent grill, the only protection was a automatic resetting thermo limit that would reset it's self, the housing around the heating elements was made out of a flammable ABS plastic, the heat element was dependent upon the blower motor in the unit which had a double shaft that also turned the fan blade for the condenser air, if at any time this blower was stopped I.E motor failure, fan blockage, or even if the selector switch was put partway between selections, the heating element could still operate and would heat up till the automatic hi limit cut out, at this time it would cool and turn the heating element back on, each time this went through a heating cycle the plastic housing would soften and droop a little closer to the elements, and after enough cycles the plastic housing would come into contact with the heating element and combusted in to a fire.

The problem with identifying the cause was because this burning plastic would drip down to what ever was combustible below the unit causing the fire to appear as it started below these units, and burned up to the unit, after a demonstration of a new unit by putting the selector in the middle and letting the unit catch fire at a local fire house safe burn room, they finely put two and two together, CPSC required a recall of these units and a few other brands that used similar automatic resetting high limits.

So should we always trust how safe things are just because it has a UL label?

I don't, but at the same time I can't afford to check out everything, but if it looks unsafe I look a little deeper.
 

steve66

Senior Member
Location
Illinois
Occupation
Engineer
So should we always trust how safe things are just because it has a UL label?

No, but I don't think an online forum is the best place for Weressl to re-engineer a piece of listed equipment when he's never seen anything except the nameplate.

His comment about the interlocks had nothing to do with the original question. The OP was basically asking about the size OCP to use, and Weressl basically told him he had another problem, which isn't true. And frankly, I take offense to his tone when he said "Because you are asking me to assume."

Steve
 

pete m.

Senior Member
Location
Ohio
Just an update... ETL will be sending a field rep out to label the equipment correctly.

I had this same issue (with improper nameplate) on some free-standing refridgeration cabinets at a large grocery retailer around the area and they also had to be field labeled.

Pete
 
No, but I don't think an online forum is the best place for Weressl to re-engineer a piece of listed equipment when he's never seen anything except the nameplate.

His comment about the interlocks had nothing to do with the original question. The OP was basically asking about the size OCP to use, and Weressl basically told him he had another problem, which isn't true. And frankly, I take offense to his tone when he said "Because you are asking me to assume."

Steve

Read the OP question, but don't read anything into it.

Please take all the offense you want. I dealt with what was presented and asked you if you KNOW anything specific that was NOT presented here, do so. Three types of data may exist:

1./ Data that is presented as part of the OP - known to everybody.
2./ Information that is not presented here, but it is intrinsic part of the equipment - known to persons that are intimately familar with the equipment.
3./ Information that is not part of the OP nor is it evident from the equipment and supplied material, but part of the UL standard cited - murky water, because ETL claims that the equipment 'meets' the UL Standard. Less murky than when the equipemnt manufacturer claims that their equipment 'meets' certain Standard.

So pardon me if I am unwiling to commit to unsubstatniated data.
 
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