Inrush Current, Stadium Floodlighting

Hi All,

I realise that there are posts regarding starting motors in a staggered way, but I cannot resolve the following (Please HELP):

I have a S7-200
I have 6 DI/12 DO

SCENARIO 1
1. I0 ON - Q0 & Q7 INSTANT ON
2. I0 OFF - Q0 & Q7 DELAY OFF - 10MINS

SCENARIO 2
1. I1 ON - Q0, Q1, Q7, Q8 INSTANT ON
2. I1 OFF - Q1, Q8 INSTANT OFF
3. I1 OFF - Q0, Q7 DELAY OFF - 10MINS

SCENARIO 5
1. I4 ON - Q6, Q12 INSTANT ON
2. I4 ON - Q5, Q11 DELAY ON - 3MINS
3. I4 ON - Q4, Q10 DELAY ON - 6MINS
4. I4 ON - Q3, Q9 DELAY ON - 9MINS
5. I4 ON - Q1,Q2,Q7,Q8 DELAY ON - 12MINS
6. I4 ON - Q6, Q12 INSTANT OFF
7. I4 ON - Q5, Q11 DELAY OFF - 3MINS
8. I4 ON - Q4, Q10 DELAY OFF - 6MINS
9. I4 ON - Q3, Q9 DELAY OFF - 9MINS
10. I4 ON - Q2, Q8 DELAY OFF - 12MINS
11. I4 ON - Q1, Q7 DELAY OFF - 15MINS

SCENARIO 6
1. IF I5=OFF THEN START TIMER
2. IF I5=OFF THEN Q2,Q3,Q4,Q5,Q6 OFF
3. IF I5=OFF THEN Q8,Q9,Q10,Q11,Q12 OFF

4. IF I5=ON AND TIMER>10MINS RESTART SCENARIO X (1-5) FROM STEP 1

I know it's a lot, but I have tried many different methodologies and I keep running short.

Thanks in advance.

Is this homework ?

I'm putting together a case sample/study to see if this is possible/feasible. Basically POC.

nowhere near enough info - what are the luminaires ? HQI, SON , Mercury , SOX (Unlikely , I know ) - what sort of loadings ? position of gantry etc ? this info is necessary to determine restrike times etc

The lamp type will differ, therefore the solution will differ.
For this example I estimate a 10min delay for lamps to cool down.
I will account for 3min between each stage/cicuit startup to get to an acceptable level before switching the next level.

I have instant restrike on Q0 & Q7, so these would remain energised.
I will switch contactors, so direct load is no issue.

Don't get too tied up in technicalities, a load is a load...

latin said:

The lamp type will differ, therefore the solution will differ.

For this example I estimate a 10min delay for lamps to cool down.
I will account for 3min between each stage/cicuit startup to get to an acceptable level before switching the next level.

I have instant restrike on Q0 & Q7, so these would remain energised.
I will switch contactors, so direct load is no issue.

Click to expand...

Latin,

I'm putting together a case sample/study to see if this is possible/feasible. Basically POC.

Click to expand...

Now then after the preliminaries, what are your questions? What is the problem? What are you trying to see if it is possible?

This is what I know now:

1. You have to figure out how to turn the lights on in a stadium.
2. You did not give the total number of cirucits or the load on each circuit.
3. What is the current inrush for each load, and how much delay time should there be between the starting of each load?

All "loads" are not the same. If it is all resistance, it behaves one way. If it has inductance or capacitance components, then that is a load of a different color. If it has harmonic currents, then that is even another type of load with its own set of problems. Whether or not these additional problems exist depend on the type of lights....

1. I can handle the switching on of my relays (Q0...Q12), with delayed starting up, to handle inrush issues, and delayed switching off, to prevent plunging dark etc. in various methods and ways. It's the complexity of re-using the starting sequence that gets me.

2. I have 4 levels/stages. These comprise of two "banks" of 6 circuits = 12 circuits. Basically 6 circuits mirrored because I have two power sources supplying the load.

Level 1 = Q0 & Q7

Level 2 = Q0 & Q1, Q7 & Q8

Level 3 = Q0, Q1 & Q3, Q7, Q8 & Q9

Level 4 = Q0, Q1, Q3, Q4, Q5 & Q6, Q7, Q8, Q9, Q10, Q11 & Q12

INPUTS:
I0 = Level 1
I1 = Level 2
I2 = Level 3
I3 = Level 4
I4 & I5 for future expansion
I6 = Power Sensor/Relay 1
I7 = Power Sensor/Relay 2

The PLC will have UPS power and will not notice an outage. I have two relays as input triggers (I6 & I7) telling me when the power to either or both sides fails. Without this I have to switch off a good side to enable staged/delayed switching on again.

The inrush is not important for this, only the delay. I would merely add another circuit should my inrush be higher.

The required delay for startup is 3mins between circuits.

For polite shutdown I need circuit Q0 to remain on for 10mins extra.

Should I have a power failure to any/both (I6 & I7) sides, I need to start a counter which should timeout at 10mins. At the same time I need to set Q1 to Q12 = 0 (Q0=1). Then only after this counter has timed-out and power restored (I6=1 or I7=1) should I restart, with the manditory delays, whichever level was originally selected.

Anything left out or doesn't make sense? The more I stare at this, the worse my mind gets.

Lancie1 said:

Latin,



Now then after the preliminaries, what are your questions? What is the problem? What are you trying to see if it is possible?

This is what I know now:

1. You have to figure out how to turn the lights on in a stadium.
2. You did not give the total number of cirucits or the load on each circuit.
3. What is the current inrush for each load, and how much delay time should there be between the starting of each load?

All "loads" are not the same. If it is all resistance, it behaves one way. If it has inductance or capacitance components, then that is a load of a different color. If it has harmonic currents, then that is even another type of load with its own set of problems. Whether or not these additional problems exist depend on the type of lights....

Click to expand...

Latin,

Is that your question: How do you organize and arrange the program to provide 4 different light levels, but not allow any light circuit to start within 3 minutes of the last one? Then for shutdown, QO stays on 10 minutes, but all others go off immediately?

The easiest program organization is to have separate routines or steps for each level, and not try to reuse the small parts of the program. This program should not be so large, so that it is not necesary to minimize it by reusing parts.

If you post your Siemens program as you have it so far, then I am sure that your problem will be found.

latin said:

Don't get too tied up in technicalities, a load is a load...

Click to expand...

Oh no it's not - if this is a paper exercise then OK , so be it , but if not , you need to do more thinking- what about when you disconnect resonant loads from the bus , all sorts of nasty things can happen , what about leading and lagging phase control ? lots more to think about , but like I said if this is just an exercise and you are looking for a quick solution to sequence the outputs as you have requested ........

I have some suggestions about how to organize, lay out, and arrange your program logic. I think you are thinking about your different inputs, switches, and so on, and are forgetting about the FINAL GOAL, turning on the lights.

First, think about what is the final result: 12 Outputs that turn on 12 different light circuits. Start a new program and put in a Routine called "Outputs". It is nothing except 12 rungs with 12 outputs, one for each light circuit.

Next, think about how many different ways these 12 outputs will be turned on/off. You have said there are 4 Levels of light, so put in 4 more Steps, "Level 1", "Level 2", "Level 3", and "Level 4". For each of these Steps, add rungs to turn on an Intermediate (also called an Interposing Relay), that is active when a light circuit FOR THAT STEP ONLY should be on.

For example, for Level 1, you need two Intermediate relays, call them "Level 1 Q0" and "Level 1 Q7". Add those in, and add a 3-minute timer that is triggered when any Output goes on, and prevents ANY OTHER Ouput from going on for 3 minutes. Also, go to the "Output" step and for the Q0 and Q7 outputs, add contacts from the Level 1 Intermediate relays to control the lights for Level 1.

Now Level 1 is finished (except for the Shutoff delay). Go on to Level 2 and do it the same way, each time adding Intermediate relays for each level, as many as are required, and also adding contacts from these IN PARALLEL with the 12 outputs.

Latin, Here is a program with following features:

1. It is a Siemens program with 12 Lighting Outputs.
2. It has 4 Input Lighting Level switches.
3. Each Level consists of the Lighting Circuits as you indicated.
4. It only allows one Lighting Output to start, with a 3-minute delay before the next one can start.​
5. If power is lost on either of the two power supplies, then the lights on that supply cut off, but restart, one at a time, when power is restored.​
6. When all Lighting Level switches are turned off, Circuit 1 stays on for 10 minutes to allow operator time to exit from the stadium.​

I left out a contact on Network 4. The 10-min_Off_Delay relay N.O. contact should be in parallel with the four Level Switches, to keep the lights on 10 minutes after shutoff.

Electricity is becoming too expensive.

Project is becoming too complicated.

Solution = Daylight Games Only!

Lancie1,
A beer or coffee any day you're down South here... your solution worked, some minor tweaking regarding specific fiddly bits, but your primary solution is 100%!!! I have no idea why, but every time I used latching I landed up with all outputs going high... strange.

But many thanks again. It's amazing how many different methods I tried...

Do you want my final solution sent to you anyway, or you happy with your good work?

Ciao,
Latin.