sporlan cds epr

[Servicerunner]

Was recently on a call at a supermarket for meat walk in running too cold and freezing product. Arrived on site, checked SH (8) and found suction at 53 (404). Box temp was about 28. The EPR was throttling at (IIRC) 72%. Box SP was 32, which is normal for meat walk ins at least from what I've seen. Yet the ground meat was freezing...not solid, but you could tell it was a little frozen. Asked the butcher if he just took it out of the freezer or something like that...no, it had been ground that the previous day and was fully thawed when put into the WI. Called monitoring for this facility and told them the setpoint was low. They refused to change setpoint (stupid of me to even ask, but....). Called my boss, he said to power cycle the board the epr was landed on. Did that, and on startup the epr was at 100% and stayed there for a long time (rack suction sp is 50) then started to throttle closed and box temp did come up. But the employees were also going in and out more...dunno if cycling board power actually fixed it. Should also say I ohmed out the cpc sensor...it was correct.

Two questions: if the circuit in question has an epr and reaches sp, how far should the valve close down? I think that for some reason it isn't throttling correctly resulting the in box temp being too low. Also, can these valves fail intermittenly?

[kevincompass]

when it reaches set point it will fully close also yes they can fail intermittently it has a throttle range programed in to the controller so some times it may dip below set point. cycling the power causes the board to close all the valves essentially zeroing out the valve. in order to effectively trouble shoot this valves you need the hand held. hear is the link to the board.
http://www.emersonclimate.com/Docume...s/026-1720.pdf

[crackertech]

Set the TR to 3.

[Servicerunner]

Thanks for the replies...as far as the handheld goes, I have one on my van. Haven't used it yet. Don't quite know how...I'm still a newb. to markets.

TR...Throttling Range? The business would never allow for that sort of EMS change. Their philosophy is...we have thousands of stores with the same setpoints...why should we change the one for the store you're at? Which actually makes sense, but can make for some long nights..............

[kevincompass]

the hand held is simple select the step rate and hold the button down to open and close the valve . if you are dealing with WalMart you can persuade them to make a change if its valid reason.

[davidadavis]

one possible issue with steppers is loosing steps, normally forcing them closed at defrost is resetting them enough. Most often the issue is on the controller side, but there are some rare circumstances when valves start loosing steps too quickly to maintain control.

[Telecaster1]

When the PID for that particular circuit calculates that setpoint has been reached, the CDS should be at 0%, unless otherwise specified. Usually when the this valve fails it is usually due to a communication error or something mechanical. When you power bump the ESR board it calibrates the steps to the reported percentage by opening and closing the valve, sometimes a successful way to correct erratic operation. You don't really need the handheld to troubleshoot unless you lose your controller or board

[WT70]

Ahhh.. CDS valves.

Walmart is using them now? I have some newer stores in my area and have not seen any in their stores.

Been working around CDS valves for a while, and honestly... I have yet to change one. (ahhh.. and will probably have one go bad tomorrow now... )

Usually I find that, as stated above, somehow it loses calibration as far as what step it is on, and a board reset usually takes care of it. Also, sensor placement or erratic sensor readings can cause problems. Technically, at setpoint, you would think it would be at zero, but if the controller is set up properly, it will not close completely. It will just throttle down to raise the evap pressure up enough to see the case warm up a little. I know with E2's.. it will learn the "optimum" percentage and once a circuit reaches setpoint.. it will keep the percentage around the optimum unless the temp goes way off.

Now,

I have a hand held from waaayyy back when I had stores with the old RMCC case controllers. Will it work with the newer boards? If so, where can I get a new cord for it? I have been using an old phone cord, but it's rj11.. which is basically a phone cable. rj 45 is ethernet. is there one in between I can make a cable with?

[davidadavis]

When the PID for that particular circuit calculates that setpoint has been reached, the CDS should be at 0%, unless otherwise specified.

Reaching set point/ supposed to be at 0% is not going to reset them. They need to "go past closed" to insure that any lost steps are compensated. As I stated, this is normally done at defrost, and normally that is sufficient.

[davidadavis]

Walmart has been using EEPR for years now, both Sporlan and Danfoss. But yes, the valves are almost never the problem and are quite reliable (other than the loosing steps).

[Telecaster1]

Reaching set point/ supposed to be at 0% is not going to reset them. They need to "go past closed" to insure that any lost steps are compensated. As I stated, this is normally done at defrost, and normally that is sufficient.

Dude I said nothing about resetting, read the post

[davidadavis]

Dude I said nothing about resetting, read the post

Well you mentioned communication and mechanical failure. The overwhelming majority of "mechanical" failures are loosing steps and it not being reset. It does not have to be done by a tech, it should be done by the EMS on a regular basis. The "mechanical failure" along with "it should be at 0%" where what I was responding to.

[bunny]

Two questions: if the circuit in question has an epr and reaches sp, how far should the valve close down? I think that for some reason it isn't throttling correctly resulting the in box temp being too low. Also, can these valves fail intermittenly?

First, the CDS (or Danfoss KVS, or Emerson ESR) valves are not EPR valves. EPR valves maintain constant pressure. Electric suction line regulators respond to temperature, and will open (reducing evaporator pressure) or close (raising evaporator pressure) in an attempt to maintain constant temperature at the sensor location.

Electric valves controllers are driven by a complex algorithm, which looks at temperature, how far that temperature is from the set-point, how quickly it is moving from the set-point, etc. Based on what the controller is sensing it will provide a signal to the valve motor, throttling open/closed in an attempt to maintain that constant temperature. Once the discharge air temperature is at the set-point, the controller will cease any signal to the motor, keeping it at whatever position it was at last. The valve will not move open/closed again until the temperature strays from the set-point enough for the controller to require valve opening/closing to correct it.

I know with E2's.. it will learn the "optimum" percentage and once a circuit reaches setpoint.. it will keep the percentage around the optimum unless the temp goes way off.

This is not true. The controller will look at the valve history and detect what seems to be the "optimum" percentage opening, but it only uses this information in the instance of an interface board failure...and at that time it will default to the optimum percentage opening in an attempt to maintain temperature until the faulty board can be replaced.

There is no direct linkage between the electric valve and the controller to insure that the number of steps the controller determines the valve requires to be open is in fact happening. If the controller requires the valve be open 2480 steps, there's no way it can verify that the valve is really open that amount. It's important that the valve and the controller be in sync to insure that the lost step phenomenon does not occur.

The best way to insure this doesn't happen is to use the handheld device to drive the valve 100% closed, and then manipulate the controller such that it signals the valve to be 100% closed. At this point the two are in sync. Then put the circuit back into normal operation.

The fact that the Sporlan, Danfoss and Emerson valves all have total valve steps that are different from each other leads to real problems if the controller is not set up to control the actual valve that is in the system. The ESR-8 valve has 800 total steps...the CDS-17 has 6386 total steps. The Einstein controller is configured with the Emerson valve as the default. If a Sporlan valve is being used, and the default is not changed, it will prevent the Sporlan valve from ever opening more than 1/8 of its total steps.

[davidadavis]

I agree with everything bunny, but it is the controllers that are used make them "temperature controllers." There are some applications where they open close on pressure so become pressure regulators. Also, the difference between stepper expansion valves and CDS/KVS are minimal. Normally just the cone shape. Maybe just call them modulating on off valves?

[Servicerunner]

So if I used the handheld to drive the valve 100% closed, and then overrode the discharge air sensor to a value much lower than set point for the circuit in question...the valve and controller would be in sync?

[steve wright]

Most of my experience is with the Sporlan CDS valves

I have found that when you have to reset the control board (or power it off) often that you generally end up replacing the operator (motor). My experience is that after that the resets end.

I must say that is very rare to have the motor fail.

This is assuming that like others have said that everything is setup right.

[bunny]

So if I used the handheld to drive the valve 100% closed, and then overrode the discharge air sensor to a value much lower than set point for the circuit in question...the valve and controller would be in sync?

If the "much lower set point" would result in the valve closing...yes.

When power is removed from the interface board, and the restored, it will automatically drive the valve closed. If you do this after driving the valve closed with the handheld device, then the two will be in sync.

There should be no danger in damaging the valve or motor doing this. Once the valve port is 100% closed, further driving the motor does not cause any damage.

[Phase Loss]

I just replaced a EEPR in a dual temp case the other day.

There was a Sporlan SDR-3 in the case, the circuit was set for medium temperature mode & the PID would call for 0% EEPR positioning once the case temperature dropped below setpoint of 30*. However, the case temperature would continue to fall to 4*.

I'd power cycle the EEPR board a few times & re-initialize the valve through the EMS & drove it closed via~ a handheld...

each way, the valve would work for a few cycles, but within a few hours, the valve would loose steps and freeze out the case again.

Cut'er out and put in a CDS-9, works great now.

5 other SDR-3 valves in that dual temp circuit work great, that one would just loose its steps.

[jpsmith1cm]

I just replaced a EEPR in a dual temp case the other day.

There was a Sporlan SDR-3 in the case, the circuit was set for medium temperature mode & the PID would call for 0% EEPR positioning once the case temperature dropped below setpoint of 30*. However, the case temperature would continue to fall to 4*.

I'd power cycle the EEPR board a few times & re-initialize the valve through the EMS & drove it closed via~ a handheld...

each way, the valve would work for a few cycles, but within a few hours, the valve would loose steps and freeze out the case again.

Cut'er out and put in a CDS-9, works great now.

5 other SDR-3 valves in that dual temp circuit work great, that one would just loose its steps.

This seems to be a very common problem, particularly with H/P dual temp islands in my area.

I have taken to carrying a couple of CDS and SDR motor kits because of it.

[steve wright]

Actually the motor and control board are not synchronized are they, doesn't the board drive the motor a certain number of steps regardless of where the motor is positioned?

I'm thinking the motor is tight or otherwise sticking, what you all think?