Mazzer Major + Gralab 450? Will it work?

#1: Post by **jchung** » March 25th, 2016, 2:40 pm

So I'm continuing to work on my project Mazzer Major. Its been converted from doser to doserless. And now I'm looking at getting a timer for it. I understand that Auber has several timers that will work, but they seem to require a bit more wiring than using a Gralab 450. Unfortunately it looks like the Gralab 450 is rated for a max 600W load. Give the motor in the Major is 650W, will the Gralab 450 work? If not, is there a way to get the Gralab 450 to work? e.g. I've read about a guy using an SSR to use the Gralab 450 with his Robur. But I'm not sure about the specs for an SSR to use with the Gralab 450 and a higher rated grinder.

Thanks!

#2: Post by **Marcelnl** » March 25th, 2016, 6:09 pm

Not sure if it will damage anything but my major is running from a 80ies Philips darkroom timer, totally analog and definitely not rated for 650W. If the SSR has a high enough rating you should be fine but I imagine it's OK without too unless you run your major for long periods (like In a business)

#3: Post by **turtle** » March 25th, 2016, 8:56 pm

which major do you have timer or manual?

If it is the standard on/off you should be fine.

If it is a timer version you might have issues with a DR timer.

Auber makes a different timer unit for the timer model as well as one for the manual type grinders

I've run my super jolly on both auber and gralab 450 without issues. Gralab is a bit of a PITA as it "forgets" everything when you power it down so each time you turn it on you have to set up the clock/timing back to fraction of seconds (default is second count down which is not too good for hitting your target weight)

Auber is a SSR type switching unit.

March 26th, 2016, 12:29 am

Mick,

My Major is actually the "auto" doser version. I've removed the doser and at the associated switches. I've jumped the connectors for the bottom switch so that the dial on the side retains its On/Off/Grind behavior. But I can jump the other connectors also so that the dial is a straight On/Off. If I were to go with the Aubers, I'm a bit undecided as to whether I should go with the J72MA or the JSL-72. Not sure if the J72MA is worth the additional cost.

Thanks for the info about the Gralab losing its setting when its powered off. Its good to know.

Do you think the Gralab 450 will be able to handle the Major?

Thanks!

March 28th, 2016, 2:23 pm

Ok. My Gralab 450 arrived today. I converted my Major's switch from Off/On/Start to a straight Off/On. Plugged it into the Gralab 450 and off I went. Took a couple shots to determine I needed 6 seconds to get 18g. So far so good. Hope I don't blow anything up in the coming months.

March 28th, 2016, 6:27 pm

good to hear it works with that much current draw.

#7: Post by JK » March 29th, 2016, 1:42 am

I have a 451 and works with Robur...

#8: Post by **turtle** » March 29th, 2016, 8:51 am

The problem with darkroom timers is that they are not built for the high starting current that motors demand. Sure grinder motors (and almost all other electric motors) have a start up capacitor but the initial current demand is going to be much more than the running current once the motor has started.

darkroom timers are built for a steady current that a light bulb requires (incandescent, florescent, or in the case of a Minolta head a strobe pulse). These types of load do not have a large start up current associated with them.

I would be interested to hear the longevity of darkroom timers when running electric motors (grinders in our case).

I used my 450 for a bit while waiting for my Auber to arrive. The Auber is a low voltage timer that turns an SSR on and off. The SSR they use inside their timers have enough oomph to handle the start up current of an electric motor.

With that said...

I did blow the main fuse on my Auber once during startup. I am running a SJ manual off of it. Only happened once in the 2 years I have used it and it may have been a fluke but Aubor did send me another fuse. They are not that easy to source. Can't recall the specs on it but it is a bit of an odd ball fuse.

And, yes... I do have a darkroom here at casa Mick so I know a little bit about darkroom timers also

#9: Post by **Marcelnl** » March 29th, 2016, 12:49 pm

My old 5€ thrift store Philips darkroom timer has served in the line of espresso duty for over a year now, with the last two months using my Mazzer Major. The only hiccup was a fuse needing replacement after a few weeks of starting to use it (not so surprising giving the age of the thing, guess it is close to thirty years old).