Any electricians here that know anything about spa/hot tubs especially?

The transformer/power splitter/coil is buzzing like a sob. The buzzing tone would change with contact to the plug that the spa had.

The input line was a 7 foot stranded 12AWG waterproof line with a standard 120V 15A plug on it. I replaced it because this was not the wire meant for the control box which has a 16A input. I hardwired it with a length of 10/2 outdoor directly to a 30A circuit. It currently isn't switched (I've got a 30A double pole switch ready to be installed.). For now, I am using the spa'* control unit GFI and the residence breaker for power control.

With the direct 30A circuit, it now buzzes louder than ever. This isn't causing any performance issues, the heater, pumps, jets, etc work fine, much better than before than with the weaker connection, but the noise is absolutely horrible. It should also be noted that load does not affect the noise, but, as noted, line current does.

I can get model numbers, pictures etc if there is someone here than knows a good place to get replacement parts, the website for the company doesn't seem to have this exact part upon surface inspection, but I also am leaving this open to see if something else can solve it.

One thing I forgot to mention is that on the front of the control box, a light indicating a "High-Limit Tripped" was and is currently illuminated.

I'm a certified electrician.
Lets see.
The tub is wired for 120 volt 16 amps?

You wired to a 30 amp breaker with #10 wire.
Is this a 2 pole breaker and you are now powering up the hot tub to 240 volts?
The reason I ask is you mention a 2 pole switch.

The higher voltage would make the transformer buzz like mad.
The higher voltage would trip the "High-Limit Tripped" indicator.

On some hot tub there is a voltage tap for selecting different voltages.

Do you have a manual, what is the make and model number.

Yes, input is 120V, 16A.

I wired to a 120V, 30A circuit.

The double pole switch i mentioned is a 120V, 30A.

Yeah, on there, the transformer has two neutral strips, one for 120, the other for 240.

options are
120V, 16A
240V, 40A

What you're saying makes sense completely, but doesn't make sense with the way everything is configured. :?

I'll get some pictures of stuff tomorrow as well and get the model number and such ASAP.

Other consideration is grounding, there should be a bond from neutral to ground at some point for the GFI breaker.
The base may also have come loose on your control transformer causing it to buzz a bit louder.

that would be my guess, the transformer is loose and vibrating.

Yeah but he did mention at the beginning that the pitch would change when he whacked the plug suggesting a loose connection.

Mhmmm,thats correct, and now that there is no loose connection, its louder, quicker, and has no change in pitch.

I can also place my finger on the front of it and tell its coming from the inside, its mounting is not loose.

I will take a video as well.

Heres a video....

Uploaded in 3 mins, so I figure downloading won't be too bad.

133MB, right click, save as, http://media.colliercomputers.com/Spa133MB.AVI

Its a HydroSpa

Model Number: P06JA2L-3100CER
Serial Number: 051103240050

I searched the model and found this site.
http://spaforums.com/

still downloading

I watched the video.
Ok thats not the transformer buzzing thats looks like the main contact relay, either for a heater or pump. The transformer is to the upper right of that buzzing contactor.
It kinda sounds like the plunger is jammed or you have an overload condition, ie pump seized.
If its the plunger a slight rap with a screw driver handle might free it up?

Do you have an electrical multi meter?