I have a dumb question/query.
I received my Omtech 5200DG today. Six liters of distilled water, plugged in and allowing to adjust itself to my shop temp etc.
Am I correct in assuming the audible alarm plug only needs to be plugged in for it to work if necessary?
Don’t think I’m completely following the question…
The machine should be setup for some type of default values that if exceeded will cause an audible alarm on the chiller… these can be programmed by the user… I set mine down to 20C, it’s default was 25C. There are other alarm options also…
Here is a link to how to hook it up to your machine…
The user and maintenance manuals have a section on programming the alarms and the error codes…
If I missed it… or you have issues … sing out… 
Jack,
Do I understand this correctly? I need to connect the alarm on the 5200DG to the same leads/connection as the factory installed sensor?
My laser gives me water alarm with the Chiller connected and working but I did not reconnect the leads that were going to the water sensor.
I have a green light on the chiller.
Also: I do not connect anything to H3 terminal on alarm (right?)
Sorry for the Senior moment.
One wire goes to the WP1 on the Ruida, and the other should go to ground…
The connector on the chiller has a common, no and nc connections… it’s likely you have it wired to the nc connection…
Check it on the chiller… find the common, then one of the other two will show connected shorted when the machine is running… that’s the one you want…
it’s easy to get these plugs turn around when you at the front and then at the back…
All that both of them do is short the two wires… pulling the input to the Ruida low…
Make sense?
Sorry, I missed this… When everything is running, the green light is on…
The schematic shows that when the green light is on, the connection between H1 and H3 occurs. This is the two pins you need to use… in this case doesn’t matter which goes to ground or to the Ruida…
Clear?
Just to stir a little incompatibility into the mix, LightObject wires the identical connector on the back of their 600 W chiller differently:
Left and right alarm pins become open contact when alarm occurs. The middle pin is not used.
So H1 and H3 are used, but they are normally open contacts that close when the water is flowing and the temperature is under control. When an alarm occurs or the chiller power is off, they open.
I added an identical connector on the laser and wired the chiller alarm relay in series with the laser’s flow switch:
I gimmicked an earth-ground wire on the unused H2 pin in the chiller, just on principle, but left that pin unused at the laser.
Got the schematic from the CW-5200 series manual… Does Lightobj have the corrected documents? Sadly, it really wouldn’t surprise me…
I noticed in your link, there is no schematic…?
Want to be double certain?
I removed the pressure sensor and routed the two wires to the chiller…
Of course not! They apparently updated the control panel, rewrote the doc to match, and left all the alarm wiring details out of the newer version. 
I’m hoping when the machine’s flow sensor or the chiller’s flow sensor fails, it will fail open so I can figure out which one it is. Most likely, it’ll fail closed and I’ll never know. Putting the two in series improves the odds of failing safe, but not by much.
It’s not like I can hear an audible alarm these days, especially over all the other noise going on in the shop.
Would be a good idea to take the schematic out of a manual and mention the differences…
This kind of stuff burns people… doing it kind of burns me up… 
