Coughtrie CPS. 28 2D Bulkhead - Gear Tray

Another Coughtrie bulkhead to enter my stash is this BNOS CPS. 28, 28w 2D bulkhead. This thing screams quality having a cast alloy base and gear tray along with a Smart & Brown ballast and starter.

Can you see the error on the label though?

File information
Filename:	IMG_0182.JPG
Album name:	fluorescent / Control Gear
Manufacturer:	Coughtrie
Type/Model:	CPS. 28
Filesize:	1528 KiB
Date added:	11 Jun, 2019
Dimensions:	2134 x 1423 pixels
Displayed:	33 times
URL:	http://80.229.24.59:9232/gallery/displayimage.php?pid=11732
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Comment 1 to 8 of 8

Page: 1

Slyspark

[12 Jun, 2019 at 12:12 AM]

Very energy-efficient 28w 2-D gear that! Laughing

AngryHorse

[12 Jun, 2019 at 06:33 AM]

Thereâ€™s a possibility that choke is just an 18 watt though, (the usual ones used in 28 watt 2D fittings), so that total circuit will be about right?

Danny

[12 Jun, 2019 at 11:37 AM]

I love Coughtrie stuff

BC5-80

[12 Jun, 2019 at 02:09 PM]

If it's true about them using 18W chokes, that might explain why so many 28W fittings are so flickery. I see one area of cost-cutting that's uncharacteristic of Coughtrie: no PFC capacitor.

FrontSideBus

[12 Jun, 2019 at 05:02 PM]

Probably just the wrong sticker meant for HF gear?

Dave

[12 Jun, 2019 at 06:18 PM]

Same gear as whats in my CPS48, its the sort of gear that could just live on forever. The HF capacitor was optional as far as I'm aware.

AngryHorse

[13 Jun, 2019 at 07:15 AM]

Again like Nick says, you donâ€™t need a full capacitor with an 18 watt choke, Thorn didnâ€™t fit them to the 90s PP218s, opting for a tiny circuit board type one, this one here is a first for me, Iâ€™ve never seen a 28 2D drum yet, that didnâ€™t have a standard 2 foot choke in it!

fluorescent

[13 Jun, 2019 at 07:48 PM]

Magnetic ballasts are more constant current rather than constant voltage, thus most 2' 18w ballasts will run 28w 2D lamps at the correct power, as these ballasts are rated at 0.37A & a 28w 2D lamp runs at 0.32A which is within the tolerance of the ballast. I'm sure I've seen some manufacturers recommend a 3' 30w ballast for 28w 2D before (these are rated at 0.36A). I suspect this SB ballast here may be more similar to, or is actually, a 3' 30w ballast as it looks too large to be a 2' ballast.

As for the capacitor, this fitting does say on the box that it's a low power factor (LPF) version hence no capacitor. PFC capacitors are not required, all they do is.. well.. correct the poor power factor stemming from the inductive load of a magnetic ballast! Some LPF fittings may still have a small X2 capacitor across line & neutral, this is only for radio interference suppression.

2D lamps are flickery on magnetic gear due to the smaller amount of phosphor I believe, due to having very little 'afterglow', so you can see the zero point in the waveform more. Not totally sure on that one though!

I'm willing to bet the circuit watts of this fitting will be more like 33 watts, and I believe that is what it should say on the label rather than 23!

Comment 1 to 8 of 8

Page: 1

Coughtrie CPS. 28 2D Bulkhead - Gear Tray

Another Coughtrie bulkhead to enter my stash is this BNOS CPS. 28, 28w 2D bulkhead. This thing screams quality having a cast alloy base and gear tray along with a Smart & Brown ballast and starter. Can you see the error on the label though?

Another Coughtrie bulkhead to enter my stash is this BNOS CPS. 28, 28w 2D bulkhead. This thing screams quality having a cast alloy base and gear tray along with a Smart & Brown ballast and starter.

Can you see the error on the label though?