How many watt resistor need to connect ?

EIC_CONTROL

dear find attach pic

no need to connect resister just follow as it is in connection.

 how many watt resistor we need to connect ?if 4 to20ma to 0 to 10 v we need to use 500ohms resistor..

what abot watt of the resistor? .2watt resistor enough ?

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Split from How to connect 4-20mA signal from sensor to PLC or vice versa.

Hello,

Thanks for reply..

Please have a look at the architecture attached ..is it right ??

E& H thermometer model No:TR66 with  transmitter 

S7 1200 PLC (6ES7 212-1HE40-0XB0)

E &H thermometer provides 4 to 20 Ma output.

S7 1200 plc  analog input is 0 to 10 V.

0_Einstein

W = V x A = 10V x 20mA = 0.2W as you calculated.

So yeah, a 1/4 W resistor should work fine as long as any error currents cannot exceed 20mA.

I would probably go with 1/2W resistor just because they are easier to work with, and for sure will not blow under normal use, and also will last even if accidentally abused.

kmansal

EIC_CONTROL

dear find attach pic

no need to connect resister just follow as it is in connection.

 how many watt resistor we need to connect ?if 4 to20ma to 0 to 10 v we need to use 500ohms resistor..

what abot watt of the resistor? .2watt resistor enough ?

 

Dear all,

If we increase the Resistor Watt to 1 Watt for more safety , will it make any erratic readings??

kmansal

Hello,

Thanks for reply..

Please have a look at the architecture attached ..is it right ??

E& H thermometer model No:TR66 with  transmitter 

S7 1200 PLC (6ES7 212-1HE40-0XB0)

E &H thermometer provides 4 to 20 Ma output.

S7 1200 plc  analog input is 0 to 10 V.

 

0_Einstein

W = V x A = 10V x 20mA = 0.2W as you calculated.

So yeah, a 1/4 W resistor should work fine as long as any error currents cannot exceed 20mA.

I would probably go with 1/2W resistor just because they are easier to work with, and for sure will not blow under normal use, and also will last even if accidentally abused.

kmansal

EIC_CONTROL

dear find attach pic

no need to connect resister just follow as it is in connection.

 how many watt resistor we need to connect ?if 4 to20ma to 0 to 10 v we need to use 500ohms resistor..

what abot watt of the resistor? .2watt resistor enough ?

 

 

Hello,

I can recommend to be in problematic here (external site): allaboutcircuits DC problematic

Improve your knowledge there, it will be big benefit for you.

 Thank You very much Duris..

But I wish to take experienced opinion before we implementing in the control system...

Duris_I

Hello,

I can recommend to be in problematic here (external site): allaboutcircuits DC problematic

Improve your knowledge there, it will be big benefit for you.

Hello,

kmansak

Thank You very much Duris..

But I wish to take experienced opinion before we implementing in the control system...

 if you look to 2-nd post of this thread by Einstein you can see there perfect recommendation.

kmansal

Dear all,

If we increase the Resistor Watt to 1 Watt for more safety , will it make any erratic readings??

 

kmansal

Hello,

Thanks for reply..

Please have a look at the architecture attached ..is it right ??

E& H thermometer model No:TR66 with  transmitter 

S7 1200 PLC (6ES7 212-1HE40-0XB0)

E &H thermometer provides 4 to 20 Ma output.

S7 1200 plc  analog input is 0 to 10 V.

 

0_Einstein

W = V x A = 10V x 20mA = 0.2W as you calculated.

So yeah, a 1/4 W resistor should work fine as long as any error currents cannot exceed 20mA.

I would probably go with 1/2W resistor just because they are easier to work with, and for sure will not blow under normal use, and also will last even if accidentally abused.

kmansal

EIC_CONTROL

dear find attach pic

no need to connect resister just follow as it is in connection.

 how many watt resistor we need to connect ?if 4 to20ma to 0 to 10 v we need to use 500ohms resistor..

what abot watt of the resistor? .2watt resistor enough ?

 

 

 

 You may use 1 watt resistor without concern  It will not provide more safety.

kmansal

if 4 to20ma to 0 to 10 v we need to use 500ohms resistor..

Be mindful too that 4-20mA over a 500 Ohms resistor will give you 2-10V (NOT 0-10V) so you'll need to consider this in your AI scaling.

Resistor tolerance (which can be up to 20% for cheap ones) will also affect your result.

All up, I would recommend to add a 4-20mA AI card to the S7 and do it "properly"