1500 W transient suppressor — obsolete, but still specifiable
The 1.5KE27-B: Its 23.1 V reverse standoff voltage and 39.38 V clamping point at 40.5 A peak pulse current make it a fit for 24 V DC rail protection where the transient energy stays within the 1.5 kJ rating.
Clamping voltage and pulse current — the numbers that decide fit
Breakdown occurs at a minimum of 24.35 V, clamping the line to 39.38 V maximum at the rated 40.5 A peak pulse current. The 23.1 V standoff voltage sits comfortably below a nominal 24 V bus, so the diode stays transparent during normal operation and only conducts when the transient exceeds the breakdown threshold. No power line protection built in — this is a secondary-side transient clamp, not a primary mains suppressor.
Obsolete part — sourcing through independent channels
Littelfuse has listed the 1.5KE27-B as obsolete. For existing BOM lines, availability is confirmed through independent surplus and distributor inventory — each lot is date-code verified before offer.