Operation
The Siemens MPS-12 is a high-current power supply designed to provide primary 24 VDC power to the MXL System. It is rated at 12 amps and operates as an unfiltered and unregulated unit. The MPS-12 supplies the necessary power for the MXL Control Panel or PSR-1 and its associated expansion modules during normal operation. Key features include a 5 amp resettable circuit breaker on the primary input, a 15 amp fuse on the 24V output, and an integrated AC line filter for surge and noise suppression. The MPS-12 is designed to be mounted within an MXL enclosure backbox.
Installation
Safety First: Always remove power before commencing any installation procedures.
Installation Kit Contents
The MPS-12 installation kit includes the following components:
- Four #10 nuts
- Two #10 lockwashers
- Two #10 flat washers
- Two ¼" nuts
- One 14 gauge green ground strap
Power and Wiring Requirements
The MPS-12 is designed to operate from a 120 VAC, 60 Hz power source. It is essential to use a separate or dedicated circuit breaker for this unit. All wiring must be performed in accordance with local codes and Article 760 of the NEC, NFPA 70, latest edition.
Grounding: Run the earth ground from a suitable source directly to the MPS-12. Local requirements must be checked; conduit is not an acceptable conductor for grounding.
Installation Steps
- Ensure the dedicated circuit breaker for the MPS-12 is turned OFF at the mains.
- Place the mounting bracket for the MPS-12 over the two studs provided within the enclosure. (Refer to Figure 1 description).
- Secure the MPS-12 to the enclosure by slipping the flat washers, then the lockwashers, and finally the nuts over the two studs. Tighten them securely.
- Connect the AC mains to the MPS-12 terminal block:
Wire Color Terminal Connection Black 1 Hot White 2 Neutral Green 3 Earth Ground - Install the 14 gauge green ground strap. Attach the spade lug side to Terminal 3 (green, earth ground) of the MPS-12. Secure the ring lug side of the ground strap to the nearest available stud in the enclosure. The stud size may vary; nuts for both #10 and ¼" studs are provided. The ground strap is designed to be long enough for all applications, and its ring lug is compatible with both #10 and ¼" studs. For optimal installation, secure the ring lug under one of the lockwashers and nuts that fasten the MPS-12 itself.
- Module Connections:
- When used with a PSR-1: Connect the 8-wire cable from the MPS-12 to the PSR-1 at connector P10.
- When used with an MMB-2/-3 or SMB-2: Connect the 8-wire cable from the MPS-12 to the MMB-2/-3 or SMB-2 at connector P14.
- When used with an MMB-1 or SMB-1: Connect the CIA-12 Cable Adapter (P/N 500-692825) to the 8-wire cable coming from the MPS-12, and then connect it to the MMB-1 or SMB-1 at connector P1.
Diagram Descriptions
Figure 1: MPS-12 in MXL Enclosure
This diagram illustrates the physical mounting of the MPS-12 power supply module within a Siemens MXL enclosure. It shows the MPS-12 unit positioned against the enclosure wall, aligning with mounting studs. The assembly sequence for securing the unit is depicted: a flat washer is placed on the stud, followed by a lockwasher, and finally a nut. The diagram labels the MPS-12 unit, the MXL enclosure, the mounting studs, and the hardware components (flat washer, lockwasher, nut).
Figure 2: Front of MPS-12
This diagram shows the front panel layout of the MPS-12 power supply module. Key features labeled include: the terminal block with terminals 1, 2, and 3 for AC mains connection (hot, neutral, ground); a 5 AMP resettable circuit breaker; a 15 AMP fuse; and connection points for power cables to various Siemens modules (PSR-1 at P10, MMB-1/SMB-1 at P1, MMB-2/SMB-2 at P14, MMB-3 at P14). A prominent warning label advises to disconnect power before removing the terminal block protection. The diagram also indicates the 14-gauge green ground strap connection.
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