Siemens LMV 5 Series, Technical Instructions, Page: 227 / 374

LMV Series Technical Instructions
Document No. LV5 ‐ 1000
SCC Inc. Page 19 Section 7
VSD Will Not Operate
If the VSD will not operate the blower (blower will not spin) when the LMV52 standardization is
activated, check the following:
1. Ensure that the VSD is activated through the following menu path in the LMV52:
Params & Display > RatioControl > Gas/Oil Settings > VSD = activated
2. The VSD cannot standardize if the safety loop is open. Check that the safety loop is closed
by making sure there is 120 VAC on terminal X3 ‐ 03.1. If there is not, check the limits in the
safety loop and the burner flange to see which limit is open.
3. Ensure that the LMV52 is not in alarm. If so, reset the fault and attempt to standardize
again.
4. Verify that the 0/4 ‐ 20 mA signal and the run/stop contact wired between the VSD and the
LMV52 are wired correctly. See Section 2 for more information on wiring.
5. Verify that the three ‐ phase motor wiring between the VSD and the motor is correct.
6. Verify that the VSD is set up properly for the motor it is driving. Specifically, check the
following:

The VSD should be spanned so that 0/4mA equals 0Hz and 20mA = 62Hz (on a 60 Hz
grid frequency). See Section 5 for more information.

The VSD is in remote mode so that it looks for a 0/4 ‐ 20mA signal and a run/stop
contact. Closing the run/stop contact should cause the VSD to operate the motor.
7. Disconnect the analog signal and run/stop contact wires between the VSD and the LMV52.
Use a handheld 0/4 ‐ 20mA source and a toggle switch to verify that the VSD responds to a
contact closure and a varying 0/4 ‐ 20mA signal.
If the VSD does not respond, correct the configuration of the VSD.
If the VSD responds to the contact closure and the varying 0/4 ‐ 20mA signal,
then go to the next step.
8. With the wires between the LMV52 and VSD still disconnected, use a multi ‐ meter to verify
that the LMV52 outputs about 19.5mA during the standardization (see note below). Also
verify that the run/stop contact in the LMV52 closes and remains closed during the
standardization.
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