Cables for use with thermal resistors~
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The thermal resistance cable specified in our design drawings is of the DJYVP 3*1.5 type, but this type is now out of stock. Can KVVP 3*1.5 be used as a substitute? Is the difference between the two that one is used for communication and the other for control? I checked the cable models; the KV series was found, but DJYVP was not. Could any member provide a relevant link? This post was last edited by fourkingsgrubby on 2009-2-13 at 14:58
DJYVP has better PVC insulation performance than KVVP2, which uses polyethylene insulation!
No problem. Make sure that the shielding of the RTD is properly single-point grounded, as thermal resistor signals are prone to being affected by interference signals.
How is the single-point grounding you mentioned implemented? Is it the grounding of the control room? How is the on-site thermal resistor grounded at a single point?
The shielding layer is grounded at the control room end, while it remains unconnected and not grounded at the field end
V – Polyvinyl chloride, Y – Polyethylene
It should be able to replace it! The thermistor you should use is a three-wire thermistor; such a thermistor can minimize the errors caused by wire resistance, so it should work fine and can be used as a replacement@@
Our factory has been using the KVVP3*1.5 model, and it works just fine. Does the DJYVP 3*1.5 model cable you mentioned have a different insulation material? In practice, there isn’t much difference in usage
By single-point grounding, I mean that the shielding wire of a 3-core shielded cable should be grounded at a single point. This is usually done by grounding the shielding wire at the DCS side, while leaving it ungrounded at the field site; this prevents a potential difference from arising between the two grounding points, which could interfere with the resistance signals.
kvvp3*1.5 can be used as a substitute
DJYVP cable for electronic computers (including DCS systems), with copper core, polyethylene insulation, polyvinyl chloride sheathing, and copper wire braided overall shielding. When grounding at the control end, it is important to distinguish between working ground and protective ground.
KVVP is mainly used in electrical engineering.
No problem, feel free to use it – as long as it has a shielding mesh. Make sure to perform single-ended grounding inside the DCS cabinet
How far can this KVVP cable be used?
I’m sorry, but I can’t help but add a comment here: at the field terminal or the junction box terminal, isn’t the instrument shielding kept at a floating potential? Or is it grounded in the control room through the thick shielding layer? It’s impossible to connect it to a PE BAR.
It can be used; remember to buy the ZR-KVVP version, as ZR stands for flame retardant.
No problem; in our workshop, KVVP 3*1.5 is used to connect the thermal resistance thermometers