Carrier MPC Open XP Series, Installation And Startup Manual, Page: 18 / 50

Installing the MPC Open XP
MPC Open XP
MPC Open XPIO48/816 CARRIER CORPORATION ©2019
Installation and Start-up Guide All rights reserved
14
Wiring inputs and outputs
WARNING Do not apply line voltage (mains voltage) to the controller's ports and terminals.
See Appendix A (page 34) to print a blank wire list.
Inputs
The MPC Open XP and expanders have universal inputs that accept the signal types described below.
Signal Type Description
Thermistor 1
Precon type 2 (10 kOhm at 77°F). Input voltages should be from 0.489 Vdc to 3.825 Vdc
for thermistors.
Dry contact A 5 Vdc wetting voltage detects contact position, resulting in a 1 mA maximum sense
current when the contacts are closed.
0–5 Vdc
0–10 Vdc
The output impedance of a 0–5 Vdc or a 0–10 Vdc source must not exceed 200 Ohms.
The input impedance of the MPC Open XP is approximately 20 kOhm.
0–20 mA The input resistance on the positive (+) terminal is 250 Ohms. The Aux Power Out
connector is capable of supplying 24 Vdc to multiple 4–20 mA transducers, but the total
current demanded must not exceed 200 mA. If the voltage measured from the Aux Power
Out connector to Gnd is less than 18 Vdc, you need to use an external power supply.
RTD 1
Platinum - 1 kOhm at 32°F (0°C)
Nickel/Iron - 1 kOhm at 70°F (21°C)
Balco TS8000 - 1 kOhm at 70°F (21°C)
Input voltages should be from 0.6–1.2 V
NOTE For improved accuracy, Carrier recommends using an external current transducer-
type RTD, when RTD's are required with the MPC Open XP. Be aware that milliamp-type
sensors require different jumper settings and different wiring arrangements.
Pulse counter
2
Pulse counting up to 40 pulses per second.
Minimum pulse width (on or off time) required for each pulse is 12.5 msec.
1
To use a thermistor or RTD not listed above, you can set up a custom translation table for your sensor.
2 The MPC Open XP can perform pulse counting for dry contact or voltage inputs if you assign the input to a Pulse
to Analog Input microblock.
NOTE If you have one or more RTD's connected to the inputs, the total current draw of all Thermistor, RTD, and
Dry contact devices wired to the inputs should not exceed 10 mA. Exceeding this limit affects the accuracy of the
RTD's. Use the following approximations as a reference:
•
10 kOhm Thermistor draws approximately 0.334 mA.
• 1 kOhm RTD draws approximately 0.834 mA.
•
Dry contact draws approximately 1 mA.
For example, if using an expander with 12 RTD's connected to the inputs, the remaining 4 inputs cannot be used.
This assumes negligible wiring impedance (<10 Ohms) for each RTD input, with up to 100 feet of 22 AWG cable.