The X-ray sources used on the older Physical Electronics (PHI) XPS systems use a heat exchanger which circulates air-cooled water to keep the X-ray source from overheating.
If your 16-020 or 16-050 heat exchanger shuts down there are only a few things that can cause that issue. This blog post will explain how to isolate the problem.
The 32-095/96 X-ray source control has two interlocks that will shut down the heat exchanger. The first is a vacuum interlock that connects from J2 interlock on the back of the 32-095/6 to setpoint 3 in the DGCIII ion gauge. That set point is typically set to 5 X 10-7 Torr. To bypass the vacuum setpoint, turn off the 32-095/6 main power and remove the J2 cable on the back of the 32-095/6, then short out pin A to B on the connector (not the cable) with a small paper clip. Note that with the vacuum interlock cable bypassed there is no protection for the x-ray source if the vacuum pressure gets too high (as in if the system vents).
If the 16-020/050 heat exchanger no longer shuts down then the issue is related to setpoint 3 on the DGCIII. It could be that the J2 cable is loose or that the setpoint relay in the DGCIII is dirty. Here is a blog post on how to clean the relays – https://www.rbdinstruments.com/blog/dgc-iii-digital-ion-gauge-control/
The second 32-095/96 interlock is the flow switch. If the water flow is insufficient then the flow switch will turn off the 16-020/050 heat exchanger. It could be that the actual flow is low, or it could be that the flow switch is defective. If your heat exchanger has a flow meter then you can see what the flow is. If you have an 04-548 source then the flow rate should be about 1.7 GPM (gallons per minute). If your system has a 10-560 source then the flow rate should be about .9 to 1 GPM. If you do not have a flow meter, then you need to remove the X-ray source lines from the source and run the water into a clean container (so that you can reuse the water) for a total time of 1 minute. With the water lines disconnected from the X-ray source the heat exchanger will shut off after 9 seconds. You need to turn the 32-095/6 off and then back on to get the water flowing again. One you have 1 minutes’ worth of water, measure it and then you will know the GPM. Then put the water back into the heat exchanger.
If the GPM is low, then you may have some obstruction, or the deionizer cartridge or particle filter may need to be replaced (RBD Instruments provides them). If the water lines are green or black, they should be replaced. Here is a blog post that explains how to do that – https://www.rbdinstruments.com/blog/replacing-the-water-lines-in-a-16-050-heat-exchanger/
If the GPM is correct, then you can bypass the flow switch by turning off the 32-095/6 and shorting pins A to E on the Pump Control connector (not the cable). You also need to move the Pump power cord on the back of the 16-020 to the HV power receptacle and then the pump will turn on when the circuit breaker in the back of the 16-020 is turned ON. Remember that there would be no protection for the source if a water flow issue develops while the flow switch is bypassed. If the heat exchanger does not shut with the flow switch bypassed then the issue is related to the flow switch. It may need to be adjusted, or it may be defective.
To adjust the flow switch setpoint, turn the small, slotted screw that is inside the hole in the black housing 2 turns CW. Then see if the heat exchanger stays on. If not, try 4 turns in the other direction. If the heat exchanger still turns off, then the flow switch is bad.
RBD Instruments provides a flow switch and a power converter. The original flow switch was powered by 120 or 220 VAC, the new ones are 24V DC.
To order a flow switch kit that includes the power converter contact us here –
https://rbdinstruments.com/phi/optics-parts.html
Here is a link to a procedure on how to replace the flow switch – https://www.rbdinstruments.com/blog/tag/replace-flow-switch/
