moondoggy4
Team RC
thanks cmm1970 Dwyer gauges checks the sir flow some read L/min, you hook it up through the air hose. You are correct the 9420.040 is the new pump for the skimmers the 9400 is a old Sicce pump.
9420?
- Thread starter 90reefernyc
- Start date
FWIW, I got a fax yesterday from the factory after Shawnz ran some tests and asked for some info on his results from a Dwyer meter. 850lph is the unrestrained airflow of a pump running submerged but not connected to a skimmer- i.e. no backpressure. When connected to our 9420 with the backpressure from the column of water the result is about 500-600lph.
moondoggy4
Team RC
Thanks Roger
I got further clarification from Mr Tunze and I will post a pic of the air flow gauge reading in use on a 9460. The key point is the air flow varies with head, install, depth, etc. -
The following reasons could be responsible for the dispute:
I.) We have detected, that the air flow meter is very important. The resistance reduces the air flow much. The Sander unit costs about 50-100 l/h, but we did not calculate this for our measuring. You can check this by the following:
The air flow meter shows at the watt meter a load; this is about 1 to 1.5 Watt. When you reduce the hose at the skimmer pump a little, so that the watt meter goes up for 1 to 1.5 Watt you can see the flow goes down for about 50 to 100 l/h.
I suppose that the guys use a big air flow meter which has a big load and reduces a lot of the air flow, much more than the sander unit. This could explain the difference. With the unit I did send, you can check this. Claude did tell me that he knows those big air flow meters which have this problem. I know from measuring the aquarium pumps that flow meter in general cost so much performance that units which work with induction can be used for only.
II.) The third problem is that one of the guys has a resistance in the hose.
III.) The fact that the water level in the skimmer runs against the pump is also important. The skimmer could have an internal water level which is 20cm higher than the sump level the air flow goes down as well. With our experience this reduces about 100 l/h.
The following reasons could be responsible for the dispute:
I.) We have detected, that the air flow meter is very important. The resistance reduces the air flow much. The Sander unit costs about 50-100 l/h, but we did not calculate this for our measuring. You can check this by the following:
The air flow meter shows at the watt meter a load; this is about 1 to 1.5 Watt. When you reduce the hose at the skimmer pump a little, so that the watt meter goes up for 1 to 1.5 Watt you can see the flow goes down for about 50 to 100 l/h.
I suppose that the guys use a big air flow meter which has a big load and reduces a lot of the air flow, much more than the sander unit. This could explain the difference. With the unit I did send, you can check this. Claude did tell me that he knows those big air flow meters which have this problem. I know from measuring the aquarium pumps that flow meter in general cost so much performance that units which work with induction can be used for only.
II.) The third problem is that one of the guys has a resistance in the hose.
III.) The fact that the water level in the skimmer runs against the pump is also important. The skimmer could have an internal water level which is 20cm higher than the sump level the air flow goes down as well. With our experience this reduces about 100 l/h.
The Sanders air flow meter uses a much lighter plastic egg and is designed for low pressure flow apps. I can confirm that watt meter does show a 1-2watt load of the air flow gauge and this proves the meter results in a reduction of air flow, as air flow drops, water flow and wattage increase. Any kink or water in the line will result in less than optimal airflow.
Jacob D
New member
<a href=showthread.php?s=&postid=14224692#post14224692 target=_blank>Originally posted</a> by rvitko
Great info, thanks Roger.
In that picture it appears that the air flow is ~ 800 lph and the pump water level is approximately at the centerline of the inlet on the skimmer body. Is this the ideal placement/submergence of the skimmer (9420/9440) ? Looks like that's one of the larger models pictured above.
BTW, the tracking for my pump shows delivered on 1/21. Did it find it's way to you?
Jacob D
New member
Roger,
I received the new Silence pump for my 9420 - thank you. I have the skimmer running finally, which is great. Now I'm trying to play catchup as to how I should be running it and what to expect...
Quoted from this thread....
Quoted from other recent thread...
The responses in the different threads seem to conflict. It would make sense to me that that Shawnz has the water level closer to ideal since the pump won't be working as hard. Right now I have my skimmer on the side of my sump with lower water level (top of the pump is just covered), I think I'm going to move it to the other side of the sump where the level is higher. I can measure the power draw (19-20w presently) and air flow, however I have a huge Dwyer and I'm sure it will have an impact on the air throughput.
I received the new Silence pump for my 9420 - thank you. I have the skimmer running finally, which is great. Now I'm trying to play catchup as to how I should be running it and what to expect...
Quoted from this thread....
Quoted from other recent thread...
The responses in the different threads seem to conflict. It would make sense to me that that Shawnz has the water level closer to ideal since the pump won't be working as hard. Right now I have my skimmer on the side of my sump with lower water level (top of the pump is just covered), I think I'm going to move it to the other side of the sump where the level is higher. I can measure the power draw (19-20w presently) and air flow, however I have a huge Dwyer and I'm sure it will have an impact on the air throughput.
Yes, one set of data is from Germany and one is what has been found domestically. There is either some difference between the skimmers (unintentional variations) or some difference between the 50Hz and 60Hz pumps. We are working on it right now. As the airflow increases power draw drops so I can roughly estimate you are getting 500lph.
Jacob D
New member
Just an update on my 9420... I let the water level in the sump reach a point below the nipple where the pump connects to the body, so the majority of the pump (the motor I suppose) is above water. The skimmer is only drawing 15 watts and appears to be foaming more. My non-professional opinion is that the body is slightly too tall for one pump, the foam seems to teeter-top between pushing out into the cup or gurgling at the top of the neck.
This is encouraging and it appears that by raising the skimmer (or lowering the water level) it will foam better, but I can see why the 9440 is said to be a better performer. Perhaps a third nipple an inch or two (oh no!) above the others for a single pump would work also, but I don't feel like putting any holes in my skimmer. I plan to buy the second pump at some point.
By the way, I have not noticed much if any increase in noise from the exposed motor, in fact after the first week of running the motor has become very quiet, just a slight hum.
This is encouraging and it appears that by raising the skimmer (or lowering the water level) it will foam better, but I can see why the 9440 is said to be a better performer. Perhaps a third nipple an inch or two (oh no!) above the others for a single pump would work also, but I don't feel like putting any holes in my skimmer. I plan to buy the second pump at some point.
By the way, I have not noticed much if any increase in noise from the exposed motor, in fact after the first week of running the motor has become very quiet, just a slight hum.
A lot of work has been done in the last two weeks on this problem and here is how it will be solved and what we found.
1) The manual and all technical literature will be rewritten to more accurately describe the flow, 850 lph pump only and that the installation depth, skimmer column, etc, will affect flow.
2) We found that increasing the diameter of the hose and intake nipple can create an increase in draw of about 50-100lph while on the skimmer. We are making this change.
3) We found that the airflow meter itself results in a reduction of 50-70 lph for the Sanders model and about 100lph for the Dwyer model and we can prove this be the following relationship: The water and air flow are in a linear relationship with the wattage, the higher the wattage the more water and less air is being pumped while total volume pumped remains constant. When the airflow meter is installed the watt meter readings increase by .50- 1.00 watts, indicating that water flow has increased and air flow has decreased and we can make a rough calculation based on the relationship.
4) We found that the 60Hz model underperforms the 50Hz model and the needle wheel for 60Hz will be changed to produce a higher flow.
5) We actually found that the more deeply the skimmer is submerged, the higher the airflow, it is the backpressure differential between the water column outside the skimmer and inside the skimmer that decreases the airflow.
6) We have found that air bubbles can enter the upper bearing and cause noise and a technical change is being made to add a line which will cool and irrigate the upper bearing. This is less likely to be an issue when the pump is fully submerged and appears to have to do with the tolerances within the pump so many pumps are not affected but some are.
1) The manual and all technical literature will be rewritten to more accurately describe the flow, 850 lph pump only and that the installation depth, skimmer column, etc, will affect flow.
2) We found that increasing the diameter of the hose and intake nipple can create an increase in draw of about 50-100lph while on the skimmer. We are making this change.
3) We found that the airflow meter itself results in a reduction of 50-70 lph for the Sanders model and about 100lph for the Dwyer model and we can prove this be the following relationship: The water and air flow are in a linear relationship with the wattage, the higher the wattage the more water and less air is being pumped while total volume pumped remains constant. When the airflow meter is installed the watt meter readings increase by .50- 1.00 watts, indicating that water flow has increased and air flow has decreased and we can make a rough calculation based on the relationship.
4) We found that the 60Hz model underperforms the 50Hz model and the needle wheel for 60Hz will be changed to produce a higher flow.
5) We actually found that the more deeply the skimmer is submerged, the higher the airflow, it is the backpressure differential between the water column outside the skimmer and inside the skimmer that decreases the airflow.
6) We have found that air bubbles can enter the upper bearing and cause noise and a technical change is being made to add a line which will cool and irrigate the upper bearing. This is less likely to be an issue when the pump is fully submerged and appears to have to do with the tolerances within the pump so many pumps are not affected but some are.
Jacob D
New member
Roger,
Thanks again for the info. I have a few questions for you...
#2, #4 - How will this effect those of us who already own the skimmer?
#3 - Is there a table showing estimated air flow vs. power consumption, say for 15w - 20w?
#5 - This makes sense as it would equalize the differential that the pump sees, however definitely not the case with what I'm seeing. The deeper I submerge the skimmer the more power it draws, with a cap of about 21 watts so far. I just increased the water level by approx. 2.5 inches and the power consumption immediately jumped from 15 watts to 18 watts.
#6 - Would this cause a loud squealing noise? This happened once during the first week of running. I unplugged the pump for a few hours and plugged it back in, have not heard it since.
Both are retrofittable solutions.
Yes, in the Interzoo 2008 flyer, it is from an early prototype but the relationship is very similar.
The pump should not draw less than 16W, if so I would assume it is not getting enough water and may be cavitating.
Yes, it is a squeeling noise and this fix can be retrofitted if needed but it takes a lot of time and attention to detail, there is a quick fix if the pump is being run submerged only.
Yes, in the Interzoo 2008 flyer, it is from an early prototype but the relationship is very similar.
The pump should not draw less than 16W, if so I would assume it is not getting enough water and may be cavitating.
Yes, it is a squeeling noise and this fix can be retrofitted if needed but it takes a lot of time and attention to detail, there is a quick fix if the pump is being run submerged only.
Jacob D
New member
Hi Roger. Bringing this one back to revisit...
I have just fired up my skimmer again. Thanks to you I now have the new 9420 pump (no bypass mod) and the new needle wheel. I have the skimmer running in 10.5 inches of water (measured from the bottom of the sump to the water line). The top of the pump is approx. 1/2" below the water line. I have a nice head of white foam right to the top of the neck, but my tank is barren so there is nothing to skim out. The pump is drawing 23 watts continuously. I have not measured the air flow yet.
- Does the new pump with new impeller have the same power/air ratio as before?
- If not, what should I expect at this power draw?
- Has an ideal water depth been determined for new pump/impeller combination?
Are there any other mods we should know about?
p.s. For anyone who is interested, I have some pictures comparing the needlewheels here
I have just fired up my skimmer again. Thanks to you I now have the new 9420 pump (no bypass mod) and the new needle wheel. I have the skimmer running in 10.5 inches of water (measured from the bottom of the sump to the water line). The top of the pump is approx. 1/2" below the water line. I have a nice head of white foam right to the top of the neck, but my tank is barren so there is nothing to skim out. The pump is drawing 23 watts continuously. I have not measured the air flow yet.
- Does the new pump with new impeller have the same power/air ratio as before?
- If not, what should I expect at this power draw?
- Has an ideal water depth been determined for new pump/impeller combination?
Are there any other mods we should know about?
p.s. For anyone who is interested, I have some pictures comparing the needlewheels here
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