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Drew
01-06-2015, 01:30 AM
Good day all,

I've come acros a maneurop compressor being controlled by vsd? It's an airconditioning application where the off coil temp is controlled by a innotech sensor maintaining the temp by ramping up and down compressor via the vsd.
this is an attempt at lowering the capacity of the unit. I found the unit with a gas leak due to vibration and have noticed the unit shaking at a certain ramp up speed.
can a maneurop be controlled by vsd? If so is there a minimum speed it should have programmed in? The maneurop full speed is at 2900rpm.

thanks.

HVACRsaurus
01-06-2015, 07:50 AM
http://web.mit.edu/parmstr/Public/x/GA052-0602GB.pdf This document suggests 45 - 75 Hz

http://www.danfoss.com/NR/rdonlyres/B52465AC-E551-41C2-9AE7-51F1001F8FEA/0/CC071GB0903.pdf This one says 30 - 90 Hz

Drew
01-06-2015, 08:32 AM
Thanks for that. it seems the scrolls and the VTZ range can be speed controlled.
I have an old school MTZ compressor?

mikeref
01-06-2015, 08:42 AM
Good day all,

I've come acros a maneurop compressor being controlled by vsd? It's an airconditioning application where the off coil temp is controlled by a innotech sensor maintaining the temp by ramping up and down compressor via the vsd.
this is an attempt at lowering the capacity of the unit. I found the unit with a gas leak due to vibration and have noticed the unit shaking at a certain ramp up speed.
can a maneurop be controlled by vsd? If so is there a minimum speed it should have programmed in? The maneurop full speed is at 2900rpm.

thanks.

Variable Frequency Drive basically allows the compressor to run (RPM) on a sliding scale, in sync with the room sensor. Non VFD driven compressors start with high current consumption and run at full speed then shut off on designated temperature. VFD Kits allow the Compressor to start "Passively" and consume less energy as their speed varies.....depending on cooling/ heating requirements.

Drew
01-06-2015, 09:04 AM
Yes, great idea except for more PC boards to worry about.

Im wondering if the MTZ maneurop range should be running on a VFD/VSD?
I have seen the unit ramp up and not enjoy a certain Hz/speed.
Ill try establish what this speed is and program in a minimum Hz/speed.
Might defeat the purpose of capacity control though.

mikeref
02-06-2015, 08:43 AM
There are a number of VSD's on the market. Depending on quality and price, you can skip the frequency causing your MTZ vibration problems.

Depending on displacement, some of these Compressors start and stop with quite a shutter while working without a VFD. In one bottle shop....the Contractor before me fitted Vibration eliminators as the shut down "Rattle" caused the copper to work harden and crack.

Circuit Boards can be a drama when the Electricity is supplied by Power Stations some 800 to 1400 Clicks away....:rolleyes:

Drew
02-06-2015, 09:51 AM
The compressor was running from 0rpm to 2900rpm and was vibrating at 1800 rpm. We have set the minimum speed to 2000rpm. We have lost a big chunk of the range but at least is runs smoothly.

Glenn Moore
02-06-2015, 10:52 PM
Hi Drew
Which Model MTZ have you got ?.

Maneurop produced the VTZ compressor which has been remodelled for use with VSDs.

We initially lost a few MTZs with VSDs due to the Klixon popping . The VTZ has a number 0of internal mods which one is that they have no internal klaxon as the VSD has that function built in.
Each model ie 1 ,2 or 4 cylinder models all have slightly different speed limits

Drew
03-06-2015, 10:12 AM
Its a MTZ81. Seems to running ok now with the low limit of 2000rpm.