After entering my setpoint my chamber fails to heat up. Where should I begin troubleshooting?
As an initial step, you will want to check the controller to make sure it’s initiating the call for cooling. An F4T controller programmed for cooling should look like the picture attached below; the control mode (displayed above the setpoint in the top right) should be set to Auto and a percentage should be displayed in the output PWR bar for cooling. You can change the control mode if needed by pressing the three white dots in the top right. You will also want to make sure that the event needed to trigger cooling at the bottom of the controller (usually labeled either “Cool” or “Conditioning Enabled”) is selected.
The picture above is from a temperature-only chamber. A humidity chamber will have two different blocks on this screen, the one for temperature will be the one on the left.
On F4 controllers, the main thing to check is to make sure the 1B light on the face of the controller is lit up when the chamber is set to cool.
My controller is displaying all the correct settings for heating. What next?
Check the limit controller to make sure that’s not preventing the chamber from cooling; this step only applies if your chamber has a Watlow EZ-Zone limit controller (pictured below) as this is the only limit model on AES chambers that has a low limit in addition to a high limit. If the chamber is going beyond what the lower limit of the controller is set to, the EZ-Zone will display the word FAIL in green at the bottom:
If the limit does need to be adjusted, you can reach the lower limit menu by pressing the green arrow button until the control displays LL.S1 in green at the bottom; the number above that will be the lower limit and it can be changed from that screen with the arrow keys.
Next Steps:
- Listen to determine whether the compressor(s) is turning on; for most chamber models the compressor should come on when the chamber is set to cool down but on LH models it should come on immediately after powering on the chamber. If the compressor is not turning on, reach out to AES Support for more in-depth troubleshooting assistance.
- Make sure the chamber has enough clearance; it needs at least a foot of space in every direction in order for the cooling system to work properly.
- Verify that the ambient temperature of the room where the chamber is operating isn’t hot enough to obstruct cooling performance; the chamber will have cooling issues if the room is above 29C/84F.
- Check whether the condenser coil needs to be cleaned, if it gets dirty or dusty then that will affect cooling performance. The condenser is the coil with the fan pointed at it; depending on your chamber model it will either be vented on the back of the chamber or underneath the chamber. Examples of both types of condensers are outlined in blue in the pictures below, you’ll want to clean the side of the coil on the other side of the fan
Checking the PCB
The majority of AES chambers will have a large green circuit board in its wiring cabinet that directs the chamber’s operations; the circuit board will either be behind the side panel closest to the controller (In LH’s, BHD’s, and SD’s) or in the top compartment of the chamber (In HD’s and FD’s) Troubleshooting suggestions for the circuit board are listed below, with all relevant components outlined in blue in the picture below (Note: depending on the model your chamber’s board may not have all these components in place)
- Check whether the ¾ Amp temperature fuse has blown.
- Verify that the pilot lights related to cooling are lighting up on the board when the chamber is set to cool (Note: You’ll only see both the High Stage and Low Stage lights illuminate if your chamber goes down to -65C).
- Check whether any of the circuit breaker switches related to cooling have tripped into the OFF position.
- If you have a multimeter available, you can check whether the Sky relays related to cooling are performing properly. While the chamber is set to cooling, you should get a continuity reading when measuring between the terminals on the relay labelled COM (Common) and NO (Normally Open) and no continuity between COM and NC (Normally Closed).
For additional assistance, please reach out to the AES support or service team. You can reach us by phone at 978-772-0022 and by email at support@associatedenvironmentalsystems.com