CM 10-2/480V -pump replaces CHI 12-15/480V -pump. How ever it is NOT one-to-one replacement but requires a rebuilt-kit if pump type is changed. If original pump type is CM 10- 2/480V, the rebuilt-kit is not required.
3BHB040251R0001 is a Rebuild-kit 1 CHI to 1 CM pumps. This kit is for 9611 and 9531 WCUs' with 1 pump. 3BHB040252R0001 is a Rebuild-kit 2 CHI to 2 CM pumps. This kit is for 9611 and 9531 WCU's with 2 pumps. Kits do not include pumps.
In case WCU has 2 CHI-pumps, both pumps needs to be replaced at once. Mixing CHI and CM -pumps in same WCU is not possible