CEILING LAMP ASSEMBLY - Fluorescent round tube type

[PETERTHEEATER]

I am now buying in the electrical lighting, switches and outlets for a new house and have a requirement for six circular ceiling mounted lamp fittings, the type that take a 32w circular fluorescent tube.

In the past, units that I bought for another house came complete with ballast unit and starter and were wired needing only connection and a tube but those that my wife has brought home are DIY kits with no instructions!

There are three components; a base plate, a surround trim and a glass dish cover. Supplied in a bag are various screws, nuts, washers and clips. Ballast units had to be bought separately.

Since there is no instruction sheet or diagram (I checked all six boxes) I have to reckon how to assemble the thing. electrics (installing ballast and starter and wiring) I can do but the mystery is how the glass dish is secured. There is no central hole to fit over the usual threaded stud for securing with a fancy nut leaving only that the dome is secured by some of the chromed blind nuts supplied along with three 30mm lengths of studding yet there are no holes in the surround trim.

I have tried assembling it 'trapped' between the metal base and the circular trim but that doesn't fit well.

I will go back to the store tomorrow and check there display item but if one of our members out there knows then please respond.

The units are made by PEMCO Thailand.

[Crossy]

Like this?

Close up of the dome fixing arrangement

The silver knurled nut holds the circular trim, the ball holds the dome (put two balls in place before installing the dome, then fit the last ball).

Sorry about the poor images, camera is playing silly beggars today.

[PETERTHEEATER]

Thanks. It must be similar to that you have shown. Sorting through the hardware the three studs have three circular flat chromed nuts that are probably spacers and there are three domed and chromed blind nuts that are tapered on the underside almost certainly to secure the class dome with one stud every 120 degrees. Just how sweaty fingers of a lamp installer tetering atop a 3m ladder is supposed to grip these smooth nuts remains a secret!

The base plate screws onto the ceiling. It is a very shallow dish the rim of which has three holes corresponding the three blind holes in the circular trim. This implies that the base plate is attached to the topside of the trim with three screws before fixing the assembly to the ceiling. That leave the glass dome to be attached to the trim but the bottom fancy side has no holes at all!

Best that I go back to the shop and look at there show item since I may end up taking them back and exchanging them and drilling or modifying them will negate that.

[PETERTHEEATER]

After breakfast this am I took another look at the lamp and found that the holes in the circular rim although appearing to be blind will 'push through' so I fitted the studs and nuts and got the glass shade to fit and hold. Only problem is that the rim of the shade rests on the chromed nuts leaving a 3mm gap all around perfect for insects to buzz in.

I went go the shop and checked their display item and it is the same so I will return the lamps unused tomorrow and exchange them for sealed units.

For CROSSY - Separate but related subject. Electronic ballast units have bee provided. At one end us a three point terminal block Line, Neutral and Ground for the input. At the opposite end is a four point terminal which, presumably, is the output to the fluo tube using that awful four pin conector. The connector supplied has four leads, two pairs each with one grey wire and one white wire. There is no wiring diagram so do I wire Grey, White, Grey, White along the block?

[Crossy]

I would wire it like that and see if it works

You are unlikely to damage the ballast or tube.

[PETERTHEEATER]

Thanks, I found a circuit diagram on the web that shows the output into the tube as two closed loops so I reckon the connection of L, N, L, N is logical.