Dear All,

                I want know total Power required for Digital input card, Digital output Card, Analog input card & analog output card. All this information is required for proper sizing for 24vdc power supply and transformer.

Case-1 for Digital Input Card (SM 321; DI 32 x DC 24 V; (6ES7321-1BL00-0AA0)

How to calculate the total power consumption for "Digital input module SM 321; DI 32 x DC 24 V; (6ES7321-1BL00-0AA0)" according to the following info mentioned in its data sheet Current. Consumption

• From the backplane bus=Max. 15 mA

Sensor selection data

   Input voltage

• Rated value=24 VDC

• "1" signal=13 V to 30 V

• "0" signal=- 30 V to + 5 V

Input current

• "1" signal=Typ. 7 mA

 Permissible quiescent current (2-wire sensor), max. 1.5 mA 

From above data I can calculate power consumption of digital input card.

 1. Backplane bus=Max. 15 mA

2. 7mA per Chanel = 7*32=224mA

 Total module current is 239mA

From above data I have some doubts.

1. What is Quiescent Current?

2. Shall I need to add quiescent current also?

 For ET-200S Digital electronic module 4DI DC24V ST (6ES7131-4BD01-0AA0)

 Current consumption

 From supply voltage Dependent on the sensor Sensor power supply output

 Output voltage

With load Min. L+ (-0.5 V)

Output current   

Rated value 500 mA

Permitted range 0 to 500 mA

 Data for selecting a sensor

Input voltage

• Rated value 24 VDC

• For signal "1" 15 V to 30 V

• For signal "0" -30 V to 5 V

   Input current

• At signal "1"    Typ. 7 mA (for 24 V)

 Permitted bias current Max. 1.5 mA

 From above data I have some doubts.

1. Current consumption  From supply voltage Dependent on the sensor I don’t understand? Please explain if possible share example.

 2. Sensor power supply output. Please explain me what is this? How it works? Whether I need to consider 500mA in power consumption?

From above data I can calculate power consumption of digital input card.

 1. Sensor power supply output??Need to add or not?

2. 7mA per Chanel = 7*4=28mA

3 Permitted bias current Max. 1.5 mA. Need to add or not?

 Case-2 for Digital Output Card (SM 322, 32DO, 24V DC, 0.5A, (6ES7322-1BL00-0AA0)

 Load  voltage  L+

Rated value (DC) 24 V

Permissible range, lower limit (DC) 20.4 V

Permissible range, upper limit (DC) 28.8 V

 Input current

From load voltage L+ (without load), max. 160 mA

From backplane bus 5 V DC, max. 110 mA

 Output Current

 for signal "1" rated value 0.5 A

for signal "1" permissible range for 0 to 40 °C, max. 0.6 A

for signal "1" minimum load current  5 mA

for signal "0" residual current, max. 0.5 mA

 Aggregate Current of Output (Per group)

Horizontal Installation

up to 40 °C, max.         4 A  

up to 60 °C, max.        3 A

 Vertical  Installation

up to 40 °C, max.    2 A

  For Digital output I am very confuse.

 1.       Input current 160mA without load means what? Or it is used only for internal circuit ? Is it right? Or something else? For calculating power consumption of module I need to consider this or not?

2.       Output Current: - 0.5A is for per channel or total current for module?

3.       Aggregate Current of Output (Per group). What is this? Please explain?

 For ET-200S Digital electronic module 8DO DC24V/0.5A HF (6ES7132-4BF00-0AB0)

 Rated load voltage L+ (from the power module) 24 VDC

 Total current of the outputs (per module) 4 A

 Current consumption

  From the rated load voltage L+ (no load) Max. 5 mA per channel

 Output current

 • At signal "1"

 – Rated value   0.5 A

 – Permitted range 7 mA up to 0.6 A

    Lamp load max. 5 W

 From above data I have some doubts.

1.       From the rated load voltage L+ (no load) Max. 5 mA per channel. Means what? Is it like 5mA current will take when my single output will on or 5mA is circuit current of module ? please explain.

2.       Output Current: At signal 1 :-   0.5A is current is it for per channel or for module?

3.       Total current of the outputs (per module) 4 A??? What is this? How it is calculated?

4.       What is Lamp Load??

  Case-3 for Analog input Card (SM 331, 8AI (6ES7331-1KF02-0AB0)

    Input Current

From backplane bus 5 V DC, max. 90 mA

 Permissible input current for current input (destruction limit), max. 40 mA

From above data I have some doubts

1.       Permissible input current for current input (destruction limit), max. 40 mA: - Please explain. What is this? I have taken this 40mA to calculate Power consumption?

For ET-200S Analog Input module 2 AI I 2/4WIRE HF (6ES7134-4MB02-0AB0)

 Current consumption

From the load voltage L+ (no encoder supply) Max. 48 mA

 48mA current consumption for all modules is it right?

Please help me to understand proper power consumption of all SM.

Regards,

Yogendra G

Hi!

Please check the following thread and my previous answer there.

Hope it helps.

Hi Olloy,

 Thanks for your help. From your previous thread I can able to understand about DI,AI & AO module power consumption but still have some doubt about Digital Out module.Please explain help me to understand DO module power calculation. As per your answer DO module Power Calculation will be 270mA. But I don't understand some technical terms of DO modules.Please see technical below technical terms.

Load  voltage  L+

Rated value (DC) 24 V

Permissible range, lower limit (DC) 20.4 V

Permissible range, upper limit (DC) 28.8 V

 Input current

From load voltage L+ (without load), max. 160 mA

From backplane bus 5 V DC, max. 110 mA

 Output Current

 for signal "1" rated value 0.5 A

for signal "1" permissible range for 0 to 40 °C, max. 0.6 A

for signal "1" minimum load current  5 mA

for signal "0" residual current, max. 0.5 mA

Aggregate Current of Output (Per group)

Horizontal Installation

up to 40 °C, max.         4 A  

up to 60 °C, max.         3 A

Vertical  Installation

up to 40 °C, max.    2 A

From above technical details please clear my doubts.

1. In output Current it say like  for signal "1" rated value 0.5 A means 32 output* 0. 5 A= 16 A is it right or this something different? please let me help to understand this term.

2. Aggregate Current of Output (Per group) :- 4 A ?? What is this?

Waiting for your reply,

Regards,

Yogendra G.

 olloy

Hi!

Please check the following thread and my previous answer there.

Hope it helps.

 Hi Olloy,

 Thanks for your help. From your previous thread I can able to understand about DI,AI & AO module power consumption but still have some doubt about Digital Out module.Please explain help me to understand DO module power calculation. As per your answer DO module Power Calculation will be 270mA. But I don't understand some technical terms of DO modules.Please see technical below technical terms.

Load  voltage  L+

Rated value (DC) 24 V

Permissible range, lower limit (DC) 20.4 V

Permissible range, upper limit (DC) 28.8 V

 Input current

From load voltage L+ (without load), max. 160 mA

From backplane bus 5 V DC, max. 110 mA

 Output Current

 for signal "1" rated value 0.5 A

for signal "1" permissible range for 0 to 40 °C, max. 0.6 A

for signal "1" minimum load current  5 mA

for signal "0" residual current, max. 0.5 mA

Aggregate Current of Output (Per group)

Horizontal Installation

up to 40 °C, max.         4 A  

up to 60 °C, max.         3 A

Vertical  Installation

up to 40 °C, max.    2 A

From above technical details please clear my doubts.

1. In output Current it say like  for signal "1" rated value 0.5 A means 32 output* 0. 5 A= 16 A is it right or this something different? please let me help to understand this term.

2. Aggregate Current of Output (Per group) :- 4 A ?? What is this?

Waiting for your reply,

Regards,

Yogendra G.

Dear YogendraG,

see the following manual on page 144:

YogendraG

All this information is required for proper sizing for 24vdc power supply and transformer.

Hi YougendraG

Calculation goes like this:

Input cards get feed with external source (example sensors).

Output cards feeds the external source (example contactors).

So for input cards you can take current consumption data from its manual, but for output card you need the manual of load which is being driven by the card (example contactor).

Digital Outputs

Let's assume that you are using DO card 6ES7322-1BL00-0AA0 and contactors 3RH1271-1BB40.

As per manual of contactor holding power for this contactor is 3.2W at 24V DC which means current consumption of 133mA.

Let's assume all 32 outputs are being used to control these contactor 24x7.

So our power consumption for 32 channel card will be 133mA x 24V * 32 ~ 102 W

Let's say you have 4 such cards so total power consumed will be 408W

Digital Inputs

Let's assume you are using DI cards 6ES7321-1BL00-0AA0

According to manual of this card each input consume 7mA for signal type 1. So let's assume that all the 32 inputs of this card are true. In this case it will consume 7mA*24V * 32 ~ 5.5 W

Let's say you have 10 such input cards so you have power consumption of 55W

So your PLC modules has power consumption of 408+55= 463 W

So to get the UPS rating in VA multiply 463W with 1.6, that is 463*1.6=740.8 VA

You can order 750 VA Transformer or UPS

Hi mopS04 / Manmeet

    Thanks for your support and nice explanation. I have done following calculations for proper sizing of 24vdc Power Supply, Transformer & UPS. Please let me whether it is correct.  For Example I have consider following Hardware.

1.       CPU 315-2 PN/DP [6ES7 315-2EH14-0AB0] – ---------------------1 no.

2.       Digital input module DI32 [6ES7 321-1BL00-0AA0] ---------------------1 no

3.       Digital output module DO32 [6ES7 322-1BL00-0AA0] ---------------------1 no

4.       Analog input module AI 8 [6ES7 331-1KF02-0AB0] ---------------------1 no

Current Consumption Calculation:-

1.       CPU 315-2PN/DP= 750mA (Current consumption (rated value) + 150 mA Current consumption (in no-load operation) + 200mA DP interface = 1100mA

2.       DI Module = 15mA( from backplane bus 5 V DC, max) + 7mA*32 = 224 (or signal "1") = 239mA

3.       DO Module = 160mA [ from load voltage L+] + 110mA [ from backplane bus 5 V DC ] + 130 mA * 32 = 4160 mA [contactors 3RH1271-1BB40]  = 4430 mA

4.       AI Module  = 90mA

Total current will be = 1100mA+239mA+4430mA+90mA = 5859mA

PLC & Module power consumption will be 140.61 W.

So required Power supply rating for PLC and Signal module will be 6A.

UPS & Transform rating will be 140.61 VA

Please let me know whether my power supply, UPS & Transform calculations correct.

DO module Doubts:-

 DO module is divided into 4 group and each group has its own supply like (L1+/1M; L2+/2M; L3+/3M; L4+/4M) and per group current capacity is 4 A. Means I can drive per group outputs up to 4A. This 4A per group current I need to consider while selecting power supply. Basically it’s totally depend on  load is connect to digital output.

Please let me know above my understanding about DO module is correct.

Waiting for your reply

Regards,

Yogendra G

YogendraG

1.       CPU 315-2PN/DP= 750mA (Current consumption (rated value) + 150 mA Current consumption (in no-load operation) + 200mA DP interface = 1100mA

2.       DI Module = 15mA( from backplane bus 5 V DC, max) + 7mA*32 = 224 (or signal "1") = 239mA

3.       DO Module = 160mA [ from load voltage L+] + 110mA [ from backplane bus 5 V DC ] + 130 mA * 32 = 4160 mA [contactors 3RH1271-1BB40]  = 4430 mA

4.       AI Module  = 90mA

Total current will be = 1100mA+239mA+4430mA+90mA = 5859mA

PLC & Module power consumption will be 140.61 W.

So required Power supply rating for PLC and Signal module will be 6A.

UPS & Transform rating will be 140.61 VA

 

you don´t need to add the "+ 150 mA Current consumption (in no-load operation)"

the terms meen that the CPU has 150 to 750 mA Current consumption

DI/DOand AI Modules:

You can not add the 5V DC with the 24 VDC. That makes no sense. The 5V from backplane bus comes from the CPU. You have it allready in your calculation!!

mopS04 

I think  YogendraG  is feeding module supply and CPU power form same source of 24V DC. There is no dedicated power supply for backplane, Just one for both module and backplane.

manmeet

mopS04 

I think  YogendraG  is feeding module supply and CPU power form same source of 24V DC. There is no dedicated power supply for backplane, Just one for both module and backplane.

 yes, thats what I think too. 

The current on backplanebus is cominig out of the CPU, and its voltage is 5V. The terms in the technical data of the module with the current from backplane is only for calculation of the power consumption on backplane bus. You can read it in SIMATIC S7-300 CPU 31xC and CPU 31x: Installation, chapter4.5:

Simatic S7-300 CPU 31xC and CPU31x: Installation

Rules: Layout of modules on a single module rack

The following rules apply to module installations on a single rack:

● No more than eight modules (SM, FM, CP) may be installed to the right of the CPU.

● The accumulated power consumption of modules mounted on a rack may not exceed 1.2

A on the S7-300 backplane bus.

 The CPU makes out of its own supply of 24V the 5V and runs the backplanebus. So the current on the backplane is allready within the power consumtion of the CPU. This is one reason why the current of the CPU is stated from 150mA to 750mA, because it depends on what moduls are running on the backplanebus.

---> every current on the backplane is irrelevant for his consumption