I am satisfied that the delivery date was short from the order. Regarding fan belts, "ordering the same production lot combination" etc. are required, but I do not know at which stage, where to request such a request. Of course it will be saved if the price is cheap.
Sound comes out when the pulley diameter is small. I feel that the sound became small when adjusting centering, parallel axis, tension. The current value was not much different from that before it was turned on, but because the belt slipping disappeared, I do not know the energy saving effect. Since it was a motor of a size not so large as to attach an inverter, we decided to use it to see the situation.
From the time of brand new twisting habit around the joint part, and attached to the blower a huge vibration got out. Distribution of such 'disengaged' items is a problem, we ask for improvements in manufacturing and inspection.