Welcome to G-TV! Today I will be showing you PID control on Eaton Cutler Hammer's H-Max
HVAC Drive. In my scenario, I would like to maintain 75 PSI in a duct with a system capable
of 0 to 200 PSI. I will set up this drive for PID control, which will be able to keep
my duct pressure at a set level. If the H-Max is in its default settings, then I will be
prompted to enter the start-up wizard on power up. This feature allows me to change what
language I can use, daylight savings, time, date, and year. If I make a mistake in any
of these selections, I can hold the back button for a couple of seconds to go back to the
previous menu. Next I can change my application. I will need to scroll to PID and continue
to the next menu. Here I can enable or disable the bypass. I will keep this enabled. Next
is where I will plug in my motor's nameplate data. This will change according to your motor
and should have different values than the ones I will plug in. I will adjust the current
to 1.8 and press ok. I'll keep the voltage at 230 volts and the motor frequency at 60
Hertz. For my RPM, I will change this to 1700. I can move the cursor to the left and scroll
down to make quicker changes. For minimum frequency, I will adjust this to 0 Hertz.
I will keep my motor frequency at 60 Hertz. Next, I will adjust my acceleration time to
5 seconds. This will make it easier to see the motor ramp up to my desired speed. Then
I will adjust the deceleration time to 5 seconds. Again, this is for a visual reference to see
the change and should be adjusted according to how fast you want the application to stop.
I will then change my "start source hand" to keypad and my "start source auto" to the
I/O terminals. I can then change my speed set point in hand mode and in auto mode. Next
is my feedback source, which is currently on analog input 2, I will change this to AI
1. This means that my voltage input reference here will simulate my pressure transducer
or feedback device that is measuring the pressure in my duct. Next is my process unit selection
which currently is in percentage. I can scroll down until I find PSI. There are many different
types of units that can be used, but for my example I am looking to create a set point
for duct pressure. I will now be able to plug in the minimum value of my process unit. As
I mentioned earlier, my system is capable of 0 to 200 PSI. I will keep this at 0 and
then change the maximum process unit to 200. I will keep the gain at 100% and keep the
integration time at 1 second. I will also keep the set point 1 source on the keypad.
The display should show ready to start. All the settings I plugged in can be changed later,
or I can hold the back key to go back. I will push ok to advance to the main menu. I will
need to plug in my set point. This is parameter number 2.9.1.2.1. Knowing the number can make
navigation easier by following the parameter number in the upper right corner. I will also
navigate through the menu. First I will go to parameter. Notice the number in the corner
is 2.1, I will scroll down until I get to 2.9, which is labeled as PID controller. If
for any reason I need to go back a step, I can press the back button for 2 seconds. I
should now be at 2.9.1 for PID controller 1, I will advance to the next menu and go
down to set points. This should be 2.9.1.2. Then I can push ok again to access 2.9.1.2.1
for keypad set point. Pushing ok will allow me to enter a subset menu where I can edit,
use the help to find out more, or add to favorites. I will push the edit key to change the value.
The blinking cursor will indicate that I am in edit mode. I will change the value to 75
PSI and then push the ok button. The number will stop blinking showing that the value
has saved. Then I will hold the back button down to go back to the subset menu. For demonstration
purposes, I will scroll down and push ok to add to my favorites. I will continue to press
the back button until I get back to the main menu. Next, I will press the hand/off/auto
key in the right corner and change the value to auto. The status menu will show 75 PSI
on the screen. I will press ok and then scroll to the motor current and press ok. This allows
me to change the display. I would like to monitor frequency, so I will scroll down to
output frequency and press ok. Then I will go down one more and change this one to PID
1 feedback. As you can see there are a lot of different options to monitor and on the
main menu is a way to monitor even more functions at once. With my desired set up, I will flip
my start switch to run the motor. Right now the motor ramped up to the maximum speed as
my feedback device is signaling to the motor that there is only a small amount of pressure
in the duct. As I slowly turn the analog input up, I can see the monitor show that my PSI
level is increasing. Once at the desired set point of 75, I can see that the motor is starting
to drop in frequency. I will then go above my set point and the motor will stop. It will
not run until my feedback senses a drop in pressure, and I will simulate this by turning
down the analog input. Eaton Cutler Hammer's H-Max HVAC Drive along with thousands of other
products and services are available at galco.com.