Replacing a Fluorescent Fitting with an HF one

[StephenW]

(I'm peering around the edge of the wall as I write this in case you shoot me! )

My single garage is lit by two twin-five-foot fluorescent fittings which I got and fitted many (20?) years ago as they were being thrown out at work. They are wired in parallel on a two-way switch.
One of the fittings has now failed (not the tube or the starter) so I will replace it.
I have been given a new fitting (twin four-foot) which is new but it is high frequency. I read the instruction leaflet (!) and it mentioned there that you shouldn't fit HF and 'traditional' on the same circuit as it could damage the HF's electronics.
Now I know as well as anyone that instructions such as this can often be a back-covering exercise and that the symptoms mentioned might occur once in a blue moon - or they might be the rule rather than the exception.
So, am I likely to damage the fitting by wiring it in place of the old one or is it unlikely (if still possible)?
If the likelyhood of damage is high then I'll fit the HF up in the loft and put the current loft fluorescent (single 5 foot traditional) in the garage.
Thanks.

 

[ricicle]

There is a possibility that the large voltages induced by a switch-start ballast could upset the electronic control gear on a HF fitting on the same circuit.

 

[333rocky333]

Seen it done loads of times in retail and commercial properties, never heard of it being a problem though,

Its likely your 20 year old light has a capacitor across the supply which may, as well as balance the power factor, could help supress the supply a bit.

 

[StephenW]

Thanks chaps - I might just give it a try.