Test 4-20 Ma Loop Integrity - Honeywell Searchpoint Optima Plus Operating Instructions Manual

MAN0905_Issue 7_07/17 Searchpoint Optima Plus with optional HART output
®
Operating Instructions
2108M0550
9. Commissioning using SHC1
Handheld Interrogator

9.5 Test 4-20 mA Loop Integrity

It is recommended that the 4-20 mA loop integrity is tested by setting the Searchpoint Optima Plus to
output an overrange current. This will confirm that there are no faults in the system that would cause a
current limit.
Note: This function will timeout after 10 minutes of inactivity.
Note: When connecting or disconnecting a multimeter, power off the Searchpoint Optima Plus, otherwise
the unit will indicate a latched warning that the 4-20 mA loop was broken. If this occurs it can be cleared
using the SHC1 Handheld Interrogator. See Clear Faults or Warnings.
1. Select Calibrate then Force 4-20.
to set the mA value to 21 mA and press Enter.
2. Use and
Searchpoint Optima Plus will now output 21 mA.
3. Check that the signal at the controller is > 20 mA, then press Enter.
4. Press Enter to release the 4-20 mA output signal.
5. Press Escape to return to the main menu.
Note: If the current at the controller is not correct, check the 4-20 mA loop connections and cabling, and
check that the loop resistance is less than 600 Ω. In current source mode, for supply voltages of 18 to
20 Vdc the maximum loop resistance is 500 Ω.
41