Anyone know if it is OK to use inline fuses or fuse blocks in the back of a panel or in a j-box enclosing a feeder. The purpose would be to provide the 5 amp protection Emon recommends for the unit.

Pardon my stupidity but, What's a "Emon Dmon" ? Without knowing what it is I would say a fuse can be installed in a lot of different places as long as it doesn't have live parts exposed to unqualified persons.

It is a local metering device. It can be used to monitor certain equipment or anything else.
I have used them most in older strip malls where there is one meter and sub panels for ind stores. This will mount in the sub panel for accurate billing to the tennant.
Basicaly just CT's to a meter.

www.ElectricSubmeter.com

Emon manufactures the Demon [short for demand monitor I think], which is a neat little self-contained digital sub meter that you can use for usage monitoring of individual branch circuits. They use small CT clamps that you clip over the load conductors.
I installed several in a condo complex a few years back. The association wanted to be able to monitor the tenant air conditioning usage during the summer months. The Demons use a small in-line fuse holder on the line to protect the meters electronics. The fuse holder is too big to fit inside the Demon’s enclosure, so it needs to be remote mounted. I had enough room to mount them on a piece of 4-inch wireway with offset nipples and put a 4” square pull box with a blank cover in between to install the fuse holder, since overcurrent devices aren’t allowed inside wireway.

Hi George. An Emon Dmon is an electronic submeter with a digital readout of KWH. Google it for more info. I had an inspector a while back tell me I couldn't put a relay or overcurrent device in s j-box, I have never spent the time to find it in the book. I checked overcurrent device/location, but didn't see it. I love this site because it saves from thumbing pages on the weekend.

Take it from me.. Keep thumbing thru the pages. There's alot of very brite people here, ask they'll tell. Blurt it out totaly wrong.. and they'll let ya know.:)

Leland, could you elaborate on that a little so eveyone knows how to avoid blurting out things totally wrong?
Thanks

Sure. Perhaps I worded it the wrong way.
Back a few yrs ago, before I registerd and was just an observer,There was someone who insisted on one item (forget the topic now ) and wouldn't let it go.The others kept correcting, and it got a little heated. Then the poster actualy looked to the book, and had egg on their face.Seems they had too much faith in hear say.

What I like about this site, is if your wrong or misinterperate the words, You folks are excellent at walking thru it so we all understand better.A true education.
In know way was it meant for anyone to be hesitant in participating in the discussions.Thats how we learn and become better Techs.

I don't beleive any of us would deny that we all learn something every day,regardless of our time in the trade.

Well said Leland.

Sometimes we get called on things that are not even in the code book. You could thumb for hours looking for it and never find it. It is really nice to save that time and tap into the incredible wealth of knowledge available here at ECN.
I agree that we should always verify the information received here by finding it in the book before applying it in the field.

Wewire:
A fused disco with correct size fuses is one option.
A fuse block in a suitable enclosure is another
'Finger safe' fuse blocks are a great choice
Midget fuses, and a finger safe block within the source panel, space allowing, would be my #1 choice.

These sub metering systems have always been a heated topic of discussion in the field. There are very few switchboards that have an extra three phase fused disconnect sitting there just waiting for the installer to hook into. Because the meters are so small there are very few places to connect the wire feeding these units to whatever method you end up using for protection. Many people have asked me if they could just slide the # 12 wires feeding the meters under a larger lug feeding something else. Unless the lug is rated for this it is in violation of the code. They also request using individual in-line fuse holders for the required fusing but then there are some disconnecting issues here as well. This type of installation always posses a dilemma to those of us who are the AHJ. Which articles of the code do we enforce and which ones do we let slide. I’d like to see what other people allow when someone asks to tap a switchboard that has no provisions for expansion and wants to feed one of these meters.

Regards,

Tony

My post above regards installing a fused disco adjacent to the gear being monitored, not necessarially a 3-pole within the 'gear'.

The 5 amp (mfg spec) fuses tend to pose situation to some EC's. IMHO, I see no issue with a 3 gang 'finger safe' midget fuse block, IF there is adequate space. A 3-pole CB is the 'disco' in this case.

Now, 'large' gear.....a Code compliant 'tap' to a fused disconnect switch....that works.

Quote:
"This type of installation always posses a dilemma to those of us who are the AHJ. Which articles of the code do we enforce and which ones do we let slide. I’d like to see what other people allow when someone asks to tap a switchboard that has no provisions for expansion and wants to feed one of these meters."

I (we) have to enforce the NEC, as adopted by NJ, as the EC's have to comply with it. I have done the 'tap' as an EC, as described above. I have not seen any sub-meter installs as an AHJ recently, but have approved 3 permit apps.