In new water and wastewater treatment facilities, few systems have a greater impact on startup success—and more potential for misalignment—than the motor control center (MCC). MCCs distribute power to essential equipment like pumps, mixers, and blowers, and they serve as the connection point between the electrical and control systems. How they are specified and who carries them in the project scope has a direct effect on how well the entire facility performs.
Traditionally, MCCs are specified under Division 26 – Electrical, while the instrumentation and control is specified under Division 40 – Process Integration and Control. This structure is common in CSI MasterFormat, the industry standard used by consulting engineers to organize specifications for construction documents. However, this division within the specifications—power in one section, control in another—often creates costly gaps.
Today’s MCCs are no longer passive power distribution systems, housing only basic components like motor starters, disconnects, and circuit breakers. In modern water and wastewater systems, they often include intelligent motor starters, networked variable frequency drives (VFDs), pilot devices such as selector switches and HOA stations, and embedded logic that interfaces directly with programmable logic controllers (PLCs) and SCADA systems over industrial networks like Ethernet/IP or Modbus TCP. This makes the MCC a fully integrated part of the control system—not just the electrical infrastructure. As a result, many consulting engineers are now specifying MCCs to be procured through the control system integrator to ensure alignment across power and control systems.
Why MCCs Belong in the Integrator’s Scope
When MCCs remain in Division 26 and are carried by the electrical contractor, the integrator is often left to adapt around decisions that were made independently—without full visibility into the control design. This creates friction and delay, especially during commissioning.
Assigning MCCs to the integrator aligns responsibility for power/control coordination with the team accountable for system performance—reducing risk across design, installation, and startup. As Greg Graves, Vice President at Revere Control Systems, put it:
“The MCC is part of the control system. It is one integrated architecture—and when we take ownership of that, we make the whole project stronger.”
Common Issues When MCCs Are Mis-Scoped
Integrators encounter the following issues when MCCs are provided by the electrical contractor without coordination for design, testing, and commissioning:
- Elevation drawings that do not match control panel layout
- Starter buckets omitted, misconfigured, or incorrectly wired
- Terminal assignments that are not coordinated with PLC I/O
- Pilot devices missing, mislabeled, or improperly installed
- Inconsistent drawing packages between vendor, EC, and integrator
- Incomplete documentation that requires reverse-engineering during commissioning
These challenges are not due to poor execution—they result from the separation of responsibilities for power and control when they should be aligned.
The Integrator’s Role in MCC Integration
The way MCCs are delivered and configured can significantly impact project agility. When MCCs are scoped with the integrator, the focus shifts from basic procurement to system-level optimization. Rather than trying to order a fully customized unit from the manufacturer—which can increase cost and extend lead times—integrators like Revere typically source standard MCC structures and build out the required functionality in-house.
This value-added customization can include:
- Harmonized electrical drawings depicting control schematics and interconnect wiring diagrams
Installing pilot devices and relays - Programming VFDs and intelligent starters
- Pre-wiring control logic and interlocks
- Ensuring compatibility with SCADA networks and communication protocols
These tasks are especially critical when working with intelligent MCCs and networked VFDs used for variable-speed pumping and aeration control in treatment processes, where even small misconfigurations in addressing or signal mapping can result in significant commissioning delays. By performing these functions in-house, the integrator can respond quickly to design updates, reduce dependency on OEM timelines, and ensure the MCC is tightly aligned with the plant’s broader control architecture. All enhancements are fully documented in the integrator’s system drawing package, so future maintenance, troubleshooting, or system expansions are not reliant on OEM submittals that may not reflect actual field conditions.
The comparison below illustrates how key responsibilities differ when the MCC is carried by the integrator versus the electrical contractor:
| Integrator-Supplied MCCs | Electrical Contractor-Supplied MCCs |
| Configures pilot devices (e.g., HOA, pushbuttons) to match control narrative | Installs devices as delivered, often requiring post-install wiring changes |
| Defines signal wiring and terminal assignments across MCC and control panel | Waits for integrator drawings to adjust wiring during startup |
| Coordinates interlocks and safety logic across systems | Relies on integrator for coordination after the MCC is built |
| Prepares NEMA Class IIB drawings mapping signals from MCC terminals to PLC I/O | Must modify or translate drawings provided by vendor or integrator |
| Assembles and tests value-added features (e.g., relays, lights, control modules) in-house | Often requires customizations to be ordered from OEM or added in the field |
When the integrator carries both the control panels and the MCC, device configuration, signal mapping, and documentation are addressed up front—resulting in a fully coordinated system. Integrators can produce a unified drawing package—often referred to as the NEMA CLASS IIB diagram—that clearly defines how signals interface between the supervisory control cabinet and the MCC. This includes detailing terminal assignments and starter bucket configurations, minimizing commissioning surprises and reducing field rework.
To avoid miscommunication and rework, consulting engineers can assign MCCs specified within Division 26 to be procured by the system integrator as specified within Division 40 using the CSI MasterFormat structure. Then, they can include a simple redirect in Division 26:
“MCCs and associated components—including motor starters, pilot devices, and VFDs—shall be furnished by the system integrator under Division 40. The electrical contractor shall install all MCCs in accordance with the integrator’s documentation.”
This structure ensures:
- One party is responsible for system functionality
- The EC has clear, accurate installation instructions
- The project team avoids gray areas during bid, build, and startup
Benefits for All Stakeholders
| For Consulting Engineers: – Fewer requests for information (RFIs) during design – Better coordination between power and controls – Clear responsibility for integration, testing, and documentation |
| For Electrical Contractors: – Straightforward installation – Fewer change orders – Coordinated drawings and preconfigured components |
| For Facility Owners: – Single point of responsibility – Fully coordinated electrical drawings – Easier troubleshooting and maintenance |
As water and wastewater facilities continue to adopt more intelligent controls, it’s time for specifications to reflect the reality of how systems function. MCCs are not just power panels anymore—they are part of the control environment. When consulting engineers assign MCCs to the integrator’s scope, they enable better documentation, tighter integration, and cleaner project delivery for everyone involved.