TRBO Repeater fan Speed

[w0en]

I have recently had installed new Vertex VXD-R70 repeater which appears to be XPR8300 clone. The main fan speed on this one is way faster and much noisier than all the rest of XPR8300's in the rack. I thought at one time I read about a switch or setting on the XPR series repeaters to have this fan speed chassis temp controlled or not, but of course I can't find it again now. Installation manual rear table list refers to fan as variable speed but is mute on how it is controlled. Does anyone with XPR8300/8400 experience know anything about this or whereabouts/existance of such a switch on the Moto branded TRBO repeaters?

[gopher]

check if the brown wire to the sanyo fan is disconnected. I have it disconnecto to run the fan at 100%

[wavetar]

I have recently had installed new Vertex VXD-R70 repeater which appears to be XPR8300 clone. The main fan speed on this one is way faster and much noisier than all the rest of XPR8300's in the rack. I thought at one time I read about a switch or setting on the XPR series repeaters to have this fan speed chassis temp controlled or not, but of course I can't find it again now. Installation manual rear table list refers to fan as variable speed but is mute on how it is controlled. Does anyone with XPR8300/8400 experience know anything about this or whereabouts/existance of such a switch on the Moto branded TRBO repeaters?

Not sure on the variable speed, but the 8400 units are definitely way louder than the 8300 units were, so I suspect the new Vertex is based on the 8400 as well.

[RFguy]

From the XPR8400 FAQ document:

Q: I received a new XPR8400 and when I power it on, the fan is blasting at Full Speed at all times. Is
my unit defective?

A: No, as described in the MOTOTRBO Repeater Installation Guide 6816814H01-J (see notes of section
1.2 Environmental Conditions at Intended Installation Site): “The XPR 8400 32 MB repeaters
manufactured after October 2010 will have a default setting of full speed for the main fan. However, the
dealer will have an option to change the setting to variable speed through an on-board switch on the
connector board assembly. The variable speed behavior is as follows: The fan will idle low and be held
constant from 10 °C to 30 °C. Between 30 °C and 45 °C, the fan will increase in speed and reach full
speed at 46 °C.”
Motorola recommends leaving the repeater at the factory default setting of Full Speed, to insure
optimal cooling of the repeater’s internal RF power amplifier. However, for installation where power
saving is required (e.g. battery operated repeaters at remote sites with low radio traffic), a fan speed
regulation switch position can be moved from Full Speed (F) to Temperature Regulated (N).

Note: The jumper is right beside the fan connector plug on the controller board

[escomm]

I'd recommend leaving the fan at default speed if the unit will be under any kind of duty cycle at all. I have not seen PAs blow up in the XPR8400 at the rate we saw them blow up on the XPR8300 but there have been a couple of failures already.

Another alternative may be to replace the fan with a unit with some better bearings. As long as the CFM and current draw ratings are the same you should be good to go