Details
94-32324 is the AAF Type B-4 battery and starter circuit relay, built to Air Corps Specification No. 32324. It is a 24 volt DC solenoid relay used as the battery disconnect (master) relay, the external power relay, or the starter solenoid, depending on the installation. Two manufacturers are documented for this type: Cutler-Hammer, whose nameplate reads TYPE B-4 / 24 VOLTS DC / BUL. 5041 H17A / SPEC NO. 32324 on a bakelite base, and Eclipse Aviation, whose version is the Solenoid Relay Type 987 Model 3 Style A to manufacturer drawing C-114370.
The Type B-4 is one of the most widely installed relays of the WWII AAF electrical system. The P-51B and P-51C model specification calls out one B-4 as the battery disconnect switch and one as the starter solenoid switch, with AN3165-1 shown as an alternate for the battery disconnect. The B-26B-35-MA carries three, for battery disconnect, external power supply, and starter. BT-13 and SNV-2 circuit diagram books list it as RELAY - BATTERY TYPE B-4, and the T-6G and LT-6G list it as the battery relay, with the larger Type B-8 (94-32424) serving as the starter relay on that airplane.
Part Number: 94-32324
Type: Relay, Battery and Starter Circuit, Solenoid
AAF Type: B-4
Specification: Air Corps Specification No. 32324
Voltage: 24 volt DC
Manufacturers: Cutler-Hammer (Bulletin 5041 H17A) | Eclipse Aviation (Type 987 Model 3 Style A, dwg C-114370)
Function: Battery disconnect / master relay | External power relay | Starter solenoid
Weight: Approx. 2.2 to 2.5 lb per period model specifications
Aircraft: P-51B Mustang | P-51C Mustang | P-47D Thunderbolt | B-26B Marauder | BT-13 Valiant | SNV-2 | T-6G Texan | LT-6G and others
Technical Orders: T.O. 03-5-25 (Cutler-Hammer) | AN 03-5-71 (Eclipse)
Related P/Ns: 94-32424 (Type B-8 Starter Relay) | 94-32276 (Type B-1 Voltage Regulator) | 94-32278 (Generator Current Control Relay) | AN3165-1 (Alternate Battery Disconnect)
Condition: NS
Important service history: T.O. 01-1-273, dated 19 October 1945, directed removal of Machined Products Company Type B-4 relay switches from all aircraft. If your relay is Machined Products Company manufacture rather than Cutler-Hammer or Eclipse, it should be treated as a display or reference item only. Check the nameplate before ordering for an airworthy installation.
Photos are for reference only. Airworthiness to be determined by an appropriately rated certificate holder.
Warranty Information
