Note that web-based summaries of standard operating
procedures are not exhaustive.
Not all of the relevant safety information is included in this document. Further training is required for safe operation and will be provided in person. |
The recirculating chiller is located on the first floor of Kolthoff. For service calls, you'll need to know the following information:
Neslab Chiller
Model: HX300A
BOM #: 390 105 311 702
Serial #: 101 303 027
Power supply: 3 phase, 208 V
Water temperature: 18 C
Software version: 000 550.36NRemote: TC400
BOM #: 604 012 000 029
Serial #: 101 323 006
You'll need a key for the janitor's closet to access the secret entrance to the storage room that houses the chiller. The lab key opens the door to the inner sanctum.
The chiller is operated via a remote control unit in the high pressure lab (room 261). To switch between the remote box and local control via the panel on the chiller, set display to read temperature, then access the setup loop by pressing 'enter' and 'next' buttons simultaneously. Scroll through to either 'remote' or 'local', and press the 'no' button to toggle the setting. At the end of the setup loop save the new settings. The chiller is started and stopped using the 'on/off' button, and the 'next' button changes the display among temperature, setpoint and flow rate.
Under normal circumstances, with coolant flowing through only the multi-anvil, the flow rate should be between 5 and 6 l/min. When a piston cylinder is in operation, the flow rate increases to ~17 l/min. A low flow warning will sound if the flow rate drops below 4 l/min. Note that turning off the chiller will automatically stop any piston cylinder experiment that's in progress.
An alarm will sound when the low water level warning is active. This usually happens at the start of a piston cylinder experiment, when the air in the hoses is flushed through the system, allowing the reservoir level to drop. When this happens, follow the instructions below to refill the reservoir.
Illustrated step-by-step instructions for refilling the chiller. Click the images for higher resolution pictures.
Open the hatch on the top of the chiller,
undo the thumbscrews and remove the lid.
Prepare 50 ppm NaNO3 coolant solution (add 1 g NaNO3 to 20 l distilled water)
fill the tank
until the water is close to the top.
Replace the covers.
If the water valves are set incorrectly in the lab so that the return valve is open at the same time as the air valve, even if the air is only open for a moment, you will need to check the chiller for potential damage. This could happen, for instance, when you're trying to flush cooling water from the piston cylinder stack and forget to turn off both water valves before opening the air valve. Even if you notice immediately and turn the air back off, you need to check the chiller. The danger is that from the lab everything may appear normal. What happens is that as air is pushed into the water pipes that return to the chiller reservoir, the displaced water fills the chiller tank, overflows and floods through the chiller, potentially causing all sorts of problems as it drips through the underlying electrical components. If you think there's some danger that this may have happened, let someone know and find out how to get things checked and cleaned up safely.
The following should be done whenever the reservoir is refilled, and at least once a month.
Have a look at the air intake at the front of the chiller.
If there's a lot of dust and debris lodged in there,
remove the front panel
and vacuum the dust out.
Models: Neil Smith, Fred Davis
ACW, 2008.
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