E-39 Alarm on 3 HP 3 Phase VFD Constant Pressure Setup

Good morning,
There's a problem here. I'm setting up a 3HP 3 phase GK3000 VFD for a constant-pressure water system. I’m getting an E-39 alarm, but it's not listed in the manual. Has anyone seen this before?

Zephyrine wrote:Hi Zephyrine,
1. Error 39 occurs because the motor frequency is lower than the sleep frequency during constant pressure water supply. What parameters have you set? Please provide us with the motor nameplate.
2. You can refer to our quick setup manual (P10.P11) for settings.
Manual: https://www.ato.com/Content/doc/gk3000-series-vfd-quick-set-user-manual.pdf

We are getting the error when bench testing the unit with a pressure regulator. We seem to be getting the error when the pressure received from the sensor doesn’t reach the sleep pressure in the amount of time of P6.42 (Constant pressure water supply blockage judgment time)
This will likely not be an issue once we have the pump integrated into the system, as the pressure will reach the sleep frequency before the P6.42 timer runs out. Is there a way to turn off P6.42?
The VFD is showing it is running at the maximum Hz, so I don’t think the motor frequency is lower than the sleep frequency during constant pressure water supply.
P6 settings are listed below.
P6.  00  2    22  0
  01  50    23  1
  02  1    24  1
  03  0    25  0
  04  1    26  0
  05  5    27  0
  06  2    28  0
  07  0    29  0
  08  0    30  0.5
  09  0    31  1
  10  0.1    32  0.005
  11  0    33  1.2
  12  0    34  0.001
  13  0    35  0.8
  14  0    36  2
  15  20    37  1
  16  2    38  5
  17  0    39  25
  18  0    40  10
  19  20    41  01
  20  80    42  60
  21  0        
I have looked through this information, and have questions regarding P6.00, P6.01, P6.30.
P6.00=0. What does PID given mean? Are we telling the VFD what the pressure is? I understand this is a selection for using P6.01 setting as the source.
P6.01=50. Is the VFD trying to target 50% of the range? How does this affect the VFD logic?
P6.30=0.7. How does this given pressure affect the VFD logic?
Currently, the VFD is sending out maximum motor frequency when the pressure is lower than the sleep pressure level (P6.37). Once the sleep pressure level (P6.37)is reached, the frequency starts to drop after the sleep pressure level continuous time (P6.38). The pressure drops to Awakening pressure level (P6.35), and after Wake-up pressure level continuous time (P6.36) the VFD motor frequency starts to climb again. Is this how it is intended to operate? Constantly cycling between the sleep pressure level (P3.37) and awakening pressure level (P6.35)? Based on this, the VFD seems to be targeting the sleep pressure level at all times, and not the given pressure (6.30), correct?

Zephyrine wrote:1. Have you set P0.01=10?
2. P6.42 is the constant pressure water supply stall judgment time setting. Its setting range is 0.1-600S, and it cannot be turned off.
3. You need to modify the settings P6.00=0, P6.04=1000, P6.05=20.0, P6.08=2.00, P6.27=1, P6.33=0.09, P6.34=0.01, P6. 41=00
4. The PID given channel selection is set by P6.01. P6.01 is the PID parameter group, corresponding to P0.01=8
The parameters after P6.30 are special parameter groups for constant pressure water supply, corresponding to P0.01=10
5. P6.01=50 is the percentage of PID 50%, P6.30 is the pressure value given 0.700MPa, the PI operation mode in PID, and the target value P6.30 is the target of PI.
For details on the operation of VFD, please refer to the P6 parameter group of the manual, pages P146-P156.
Manual: https://www.ato.com/Content/doc/gk3000-variable-frequency-drive-user-manual.pdf

Yes, I have P0.01 set to 10
Okay
Sure, that works for your example, but I am dealing with a different target pressure
We want our system to target 0.8MPa when water is flowing and go to sleep when flow stops.
P6.05=20.0 is contradictory to the quick setup manual (https://www.ato.com/Content/doc/gk3000-series-vfd-quick-set-user-manual.pdf)
P6.08=2.00 – we don’t want the pump to reverse rotation
P6.27=0 – we have P6.26 set to 0, so this shouldn’t be factored
P6.33=0.09 seems low to be an alarm threshold with our running pressure at 0.8MPa
P6.34 = 0.01 – we have this set at 0.001 to minimize alarms, but will likely raise this value closer to 0.7MPa for loss of pressure alarms in the future
P6.41=00 – The VFD does not go to sleep mode. Not sure if I am missing something here. P6.41=01 appears to be the actual pressure and allows sleep based on my trial and error.
So should I have P0.01 set to 10 or to 8?
I assume this only works if P0.01 is set to 8?
I have reviewed this information in the manual.
Thank you for your help,

Zephyrine wrote:Zephyrine,
1.P6.05 can be adjusted by itself; the factory default is 20. It is the proportional gain Kp1, which determines the adjustment intensity of the entire PID regulator. The larger Kp1, the greater the adjustment intensity.    
2. P6.08 is the PID reversal cutoff frequency; there is no need to set this parameter. You can just use the factory default value = 2.00; it will not cause inversion.
3. P6.27 PID feedback loss detection time can be set to 0, or the factory default value = 1 can be used. This does not affect use; you do not need to set it.
4. You can increase the pressure value of P6.33 by yourself.
5. P6.34 = 0.01 – We set this value to 0.001 to minimize alarms, but may increase this value closer to 0.7MPa in the future to account for pressure loss alarms.——OK, you can set it like this.
6. P6.41=00 This is the correct setting. The sleep pressure and sleep frequency must be reached at the same time to be effective, and the wake-up sleep pressure is the actual pressure.
7. You should set P0.01=10, which sets the VFD to constant pressure water supply mode.
P0.01=8 is the PID given; we set P6.01 to be also the PID given. In the constant pressure water supply mode, P6.01 is equivalent to P0.01=8.

ATO wrote:I understand. Appreciate the detailed guidance from ATO!