Inputs requiring external resistor/jumper?
I was having a conversation with someone about powered inputs and on the topic I had remembered Circon UHC series had a jumper switch and they guy said with Distech you need to add the external resistor. I think XL800 modules need external resistor... so the question what do the other vendors do?
They are probably talking about converting a 0-20 mA signal to 0-5 volts (w/ 250 ohm resistor), or 0-10 volts (using a 500 ohm resistor). Companies like ALC can handle 0-20 mA inputs, while Novar cannot (need external resistor to convert to voltage).
Don't forget ABB Drives D+ and Dcom.
Schnider Electric(TAC) needs resistor to convert 0-10v to 4-20ma.
CSI uses resitor to determind hte input value, these are built into the programmable boards.
Distech uses resistors for there 4-20ma input signal.
Distech also has jumper for output of 4-20ma or 0-10vdc
Circon older controllers need the resistors for conversion also.
KMC uses 'pullup' resistors. Rocker switches on the boards.
"Controls is a lifestyle not a job" -klrogers
Delta uses dip switches that apply different resistances.
When did Delta change to dip switches? All the controllers from Delta I have dealt with use jumpers for input/output configuration.
Delta - Jumpers
Reliable - Dipswitch (M1/M2) Jumpers (VAV/Zone/Stat) - Ext Resistor (4-20mA)
tac Andover - Dipswitch
Alerton - Jumpers
Autmoated Logic - Jumpers
tac Xenta - Software IIRC
JCI - Jumpers
"Open is as open does."
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"BACnet: integration or interrogation?"
- The Janitor
"Open protocols? You can't handle open protocols!"
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“What’s that? Aaa… open protocols? Don’t talk about…. open protocols? Are you kidding me? Open protocols? I just hope we can hardwire an interface!”
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maybe I'm using the wrong term here. The inputs on all the newer (V3.22 and up) stuff use switches that are a bit larger than a typical dip, but I dont know what else to call them. On the switch, the installer can choose between 4-20, 10k, 5v and 10v.
I always setup my inputs for voltage and use an external resistor to convert - 4-20mA signals to 1-5VDC or 2-10VDC (depending on the controller). That way I can troublshoot down the line easier with a meter rather than having to do the stupid put your meter in series with the signal thing....Just my $.02
JustJohnson- Ask yourself which method is more susceptible to inaccuracy over distance? (0-10 or 4-20)
--- now somebody here will tell you I'm just sales... but ignore that guy for now.
AHHHH! I'm deleriously tired. Delta uses jumpers, not dips. Not sure where my head was there!
justjohnson - current remains the same over the entire circuit. go with 4-20 for distances. and there are meters that will read 4-20 without getting in series.