[Cause]
The supply side detected low pressure for the second material. Normally, they will be in either of the following states.
1. The supply line (hose, etc.) has come off.
2. The low pressure limit setting is too high.
3. Low pressure limit time setting values are too short.
[Countermeasure]
Repair of supply pipes. Sets the low pressure limit to the appropriate value. Sets the low pressure limit time to the appropriate value.