LiftMaster Electrical Box Parts — Contactor Style Operators
Genuine replacement parts for the contactor-style control circuit electrical box. This is the older, relay-and-contactor control — no logic board. If your box contains a printed circuit board, you have a logic control version instead; see the L2, L3 and L4 pages linked at the bottom.
Transformers and relays are voltage specific, and the overload must match the motor's full-load amps — the rating is on the motor plate. Parts marked no longer available have been discontinued and are listed for identification only.
Box, Cover & Contactor
| Ref |
Part # |
Description |
| 1 |
03-8024-K |
Mini Contactor, 24V (K03-8024-K) |
| 2 |
10-10444M1 |
Electrical Box — models GT and GH |
| 3 |
10-10115X |
Electrical Box Cover — now supplied as the K75-10128 low profile cover |
| — |
K75-10128 |
Low Profile Cover — current replacement |
Transformers — Match Your Voltage
| Ref |
Part # |
Description |
| 4 |
21-5115 |
Transformer — 115V operators (K21-5115) |
| 4 |
21-5230 |
Transformer — 230V operators (K21-5230) |
| 4 |
K21-5460 |
Transformer — 380-460V operators |
Relays, Switches & Terminals
| Ref |
Part # |
Description |
| 5 |
23-10916 |
SPDT Interlock Switch (K23-10916) |
| 6 |
24-24-1 |
Relay, 24VAC DPDT (K24-24-1) |
| 7 |
24-115-1 |
Relay, 115V (K24-115-1) |
| 7 |
24-230-5 |
Relay, 230V (K24-230-5) |
| 10 |
42-10040 |
Terminal Block, radio (K42-10040) |
| 11 |
K42-110 |
Terminal Block, 10 position |
Overloads — Match Your Motor Amps
The overload protects the motor and must match its full-load current. Check the amp rating stamped on the motor plate before ordering — fitting the wrong one either nuisance-trips or fails to protect.
Limit Shaft & Switch
| Ref |
Part # |
Description |
| L1 |
11-10021 |
Limit Shaft (K11-10021) |
| — |
K72-12510 |
Limit Shaft Kit — complete assembly |
| — |
K75-12511 |
Limit Switch Assembly |
Options & Safety
| Part # |
Description |
| 71-2954029 |
Light Delay Kit |
| CPICARD |
CPI interface box |
| CPS-U |
Commercial photo eye |
| CPSUN4G |
Monitored through-beam photo eyes |
| CPS |
Safety eye sensors — mechanical operators |
| CPS-UN4 |
Safety eye sensors — commercial doors |
| K77-16011 |
Mounting hardware, CPS N4 |
| 65-5302 |
Pneumatic sensing edge, 22 ft, with take-up reel |
| LC-36A |
Safety eye sensors (no longer available) |
Other Electrical Box Versions
Logic Control Version 2 · L3 for T, GT, GH · L3 for J, H, HJ · MT, BMT, MJ, MH, HMJ
