Frequently Asked Questions- PM3000
The PM3000 is a three phase power quality, harmonics and flicker monitor
Click to view the PM3000 datasheet
How long can a PM3000 record for?
There is no definitive answer to this question as the variable is the detail you record, not the length of recording. One of the first things you do when setting up your logger is select the time interval.
As an example, you can ask it to record for a week or two, or if you have requested extended memory you could ask your PM3000 to record for 2 months and still get down to single cycle detail during disturbances.
Our intelligent storage technique Adaptive Store, which all of our loggers have, will then share out the memory it has available over the period and give more or less detail depending on how much memory you have allocated and the number of channels selected. Anomalies will still be recorded in relatively more detail but the trend data will become less detailed as the recording period gets longer and the number of channels increases. Allocating more memory (possible in a PM7000) or choosing once of our memory extension options (8MB, 16MB, 32MB, 64MB) will enable the unit to give even more detail over a longer monitoring time.
Adaptive Store is an intelligent compression mechanism with a 25 - 200:1 compression ratio.
The question asked is how long can the PM3000 record for? With the standard 1MB model, if you only select 1 channel it will give you about 50 days of detailed results. If you select 16 channels it will give you a week of detailed results, down to single cycle when anomalies occur. There will always be a trade off of length of recording, number of channels selected and amount of variation in activity versus the resolution of the recorded data. The Adaptive Store 'adapts' to what is going on.
As mentioned previously, we now have 4 new members of the PM3000 sub-family. The 8MB, 16MB, 32MB and 64MB memory models. More memory means more detail for longer, on more channels. This can offer enhanced profiles of dips, sags, surges and overall harmonic levels etc. as well as providing better resolution for phenomena such as Instantaneous Flicker Sensation.
Existing customers may be able to retrospectively upgrade their units.
My PM3000 batteries seem to be losing charge faster than they ought to. Is there anything I can do about this?
Please find below our guide to PM3000 Battery Maintenance
1. The PM3000 is not primarily a battery operated instrument.
2. It is designed to be on charge all the time even when stored on the shelf, using the mains lead or a charger.
3. The purpose of the batteries is to give a ten minute ride through should the power go down and to preserve the data for a realistic period when the power is removed and the unit is off.
4. The unit is normally powered off the voltage being measured. If only current is to be measured you must use a 12 volt charger plugged into the mains (or other form of power e.g. car battery) to charge the system.
5 . The main charge rate for the PM3000 is slow, 30 mA. This is the maximum rate we can use to meet the safety standards. It is the maximum rate which can be sustained indefinitely.
6. So to charge the PM3000 fully from a flat state will take several days.
7. To see if it is charging correctly go to 'Configure', 'Utilities', 'Manage Battery', 'Test charge circuit' and wait for it to give you a charging value for the Low and High rates. A fully charged unit will read about 5.4 Volts.
8. The fact that the batteries are completely flat (we consider flat to be < 4.8 V) is not catastrophic for the unit but will increase the drain on the clock battery, which will eventually need replacing. (Data will be lost if the batteries go below about 4.5V).
9. However the batteries should from full charge hold the data for about two months at room temperature.
10. When the batteries are nearly flat the operation of a charge accumulator will force the screen to shut down to stop any more drain on the batteries and leave enough charge to hold up the data. Once the unit is plugged in and the battery has reached a reasonable level of charge, the screen will once more light up. This means that after the screen has 'closed down to save batteries', it will not necessarily come alive immediately it is plugged in.
Can the PM3000 interface to my network?
Yes it can. We can provide an ethernet to Serial converter to enable your PM3000 to connect to your network. We've had a lot of success with Moxa DE311, just ask us for one.
What happens if I stop a 7 day recording after 24 hrs and start recording again with the same settings?
All that will happen, if you haven't downloaded and erased the data after your first recording, is that the detail you get during your second recording will be reduced versus the first. For a couple of recordings this is probably alright, but more than that, i.e. if you continue to do this for a week, then you significantly reduce the level of detail recorded during the subsequent recordings.
At the beginning of any recording your PM3000 will work out what level of detail is 'allowed' in order to deliver consistent detail over the entire length of the recording. This level of detail is based on how much memory is left in the unit for that recording.
If you start recording with a PM3000 with full memory available, for 7 days, it will allocate approximately 1/7th of the total memory per day. If you stop the recording after 1 day, it will have used up approximately 1/7th of the total memory available. If you then restart the recording, without erasing that first set of data, then you will have 6/7ths of the original memory available for your next recording. Again the PM3000 will try to allocate the available memory evenly over the recording period so this time, rather than allocating 1/7th of the total memory of the unit, it is allocating 1/7th of the remaining memory for each day of recording, i.e. 1/7th of the 6/7ths left.
At the beginning of the week this doesn't matter but if you continue to record for 1 day at a time without changing the recording set up (of 7 days), the remaining memory will continually be reduced by 1/7th during every recording. The more you record like this the less detail you will get on your recordings.
Our advice, if you are going to stop the recording every day, would be to set it for 24hrs and download the data each time. That way you get the same high level of detail during every recording. Otherwise leave the recording for the 7 days then download it and view either as a whole week or each 24hrs on their own later on in Pronto, the software that comes free with your unit.
Click to view the PM3000 datasheet
How long can a PM3000 record for?
There is no definitive answer to this question as the variable is the detail you record, not the length of recording. One of the first things you do when setting up your logger is select the time interval.
As an example, you can ask it to record for a week or two, or if you have requested extended memory you could ask your PM3000 to record for 2 months and still get down to single cycle detail during disturbances.
Our intelligent storage technique Adaptive Store, which all of our loggers have, will then share out the memory it has available over the period and give more or less detail depending on how much memory you have allocated and the number of channels selected. Anomalies will still be recorded in relatively more detail but the trend data will become less detailed as the recording period gets longer and the number of channels increases. Allocating more memory (possible in a PM7000) or choosing once of our memory extension options (8MB, 16MB, 32MB, 64MB) will enable the unit to give even more detail over a longer monitoring time.
Adaptive Store is an intelligent compression mechanism with a 25 - 200:1 compression ratio.
The question asked is how long can the PM3000 record for? With the standard 1MB model, if you only select 1 channel it will give you about 50 days of detailed results. If you select 16 channels it will give you a week of detailed results, down to single cycle when anomalies occur. There will always be a trade off of length of recording, number of channels selected and amount of variation in activity versus the resolution of the recorded data. The Adaptive Store 'adapts' to what is going on.
As mentioned previously, we now have 4 new members of the PM3000 sub-family. The 8MB, 16MB, 32MB and 64MB memory models. More memory means more detail for longer, on more channels. This can offer enhanced profiles of dips, sags, surges and overall harmonic levels etc. as well as providing better resolution for phenomena such as Instantaneous Flicker Sensation.
Existing customers may be able to retrospectively upgrade their units.
My PM3000 batteries seem to be losing charge faster than they ought to. Is there anything I can do about this?
Please find below our guide to PM3000 Battery Maintenance
1. The PM3000 is not primarily a battery operated instrument.
2. It is designed to be on charge all the time even when stored on the shelf, using the mains lead or a charger.
3. The purpose of the batteries is to give a ten minute ride through should the power go down and to preserve the data for a realistic period when the power is removed and the unit is off.
4. The unit is normally powered off the voltage being measured. If only current is to be measured you must use a 12 volt charger plugged into the mains (or other form of power e.g. car battery) to charge the system.
5 . The main charge rate for the PM3000 is slow, 30 mA. This is the maximum rate we can use to meet the safety standards. It is the maximum rate which can be sustained indefinitely.
6. So to charge the PM3000 fully from a flat state will take several days.
7. To see if it is charging correctly go to 'Configure', 'Utilities', 'Manage Battery', 'Test charge circuit' and wait for it to give you a charging value for the Low and High rates. A fully charged unit will read about 5.4 Volts.
8. The fact that the batteries are completely flat (we consider flat to be < 4.8 V) is not catastrophic for the unit but will increase the drain on the clock battery, which will eventually need replacing. (Data will be lost if the batteries go below about 4.5V).
9. However the batteries should from full charge hold the data for about two months at room temperature.
10. When the batteries are nearly flat the operation of a charge accumulator will force the screen to shut down to stop any more drain on the batteries and leave enough charge to hold up the data. Once the unit is plugged in and the battery has reached a reasonable level of charge, the screen will once more light up. This means that after the screen has 'closed down to save batteries', it will not necessarily come alive immediately it is plugged in.
Can the PM3000 interface to my network?
Yes it can. We can provide an ethernet to Serial converter to enable your PM3000 to connect to your network. We've had a lot of success with Moxa DE311, just ask us for one.
What happens if I stop a 7 day recording after 24 hrs and start recording again with the same settings?
All that will happen, if you haven't downloaded and erased the data after your first recording, is that the detail you get during your second recording will be reduced versus the first. For a couple of recordings this is probably alright, but more than that, i.e. if you continue to do this for a week, then you significantly reduce the level of detail recorded during the subsequent recordings.
At the beginning of any recording your PM3000 will work out what level of detail is 'allowed' in order to deliver consistent detail over the entire length of the recording. This level of detail is based on how much memory is left in the unit for that recording.
If you start recording with a PM3000 with full memory available, for 7 days, it will allocate approximately 1/7th of the total memory per day. If you stop the recording after 1 day, it will have used up approximately 1/7th of the total memory available. If you then restart the recording, without erasing that first set of data, then you will have 6/7ths of the original memory available for your next recording. Again the PM3000 will try to allocate the available memory evenly over the recording period so this time, rather than allocating 1/7th of the total memory of the unit, it is allocating 1/7th of the remaining memory for each day of recording, i.e. 1/7th of the 6/7ths left.
At the beginning of the week this doesn't matter but if you continue to record for 1 day at a time without changing the recording set up (of 7 days), the remaining memory will continually be reduced by 1/7th during every recording. The more you record like this the less detail you will get on your recordings.
Our advice, if you are going to stop the recording every day, would be to set it for 24hrs and download the data each time. That way you get the same high level of detail during every recording. Otherwise leave the recording for the 7 days then download it and view either as a whole week or each 24hrs on their own later on in Pronto, the software that comes free with your unit.
