Ensuring Reliability in Crisis

The Crucial Role of Commissioning Integrated Emergency Power Supply Systems

Initiating the setup of sophisticated emergency power mechanisms demands that the overseeing specialist, the EPSS commissioning provider (EPCx), understand relevant rules, standards, and all codes necessary for full compliance with all Authorities Having Jurisdiction. Moreover, they must have extensive hands-on experience with emergency power setups, inspections, maintenance, and integrated testing.

In emergency power systems, distinguishing between various components and systems is crucial. According to NFPA 110, which outlines Emergency and Standby Power Systems standards, an emergency power supply system (EPSS) encompasses the emergency power source distribution components (such as paralleling switchgear), over current protection and transfer switches. On the other hand, the emergency power supply (EPS) includes just the emergency power source and any distribution elements up to the transfer switches.

The traditional generator part of an EPS is often an on-site engine generator combo, capable of delivering stable power swiftly in emergencies. It is known by various names – generator, genset, emergency generator, or engine generator.

Automatic transfer switches play a pivotal role. They seamlessly switch critical building loads between two power sources, usually the utility company and the EPS. This process can be automatic or manual, depending on code allowances.

An integral aspect of emergency power systems is the distribution equipment tailored for these systems. For instance, paralleling switchgear distributes the load among several synced gensets. Every EPSS design will invariably include an on-site source or genset.

The electrical system commissioning should span all project phases, with early involvement ensuring that client goals and operational requirements are integrated from design to construction and system handover. While the EPCx may review and contribute to design, the primary responsibility for adhering to construction standards rests with the engineer of record (EOR) and the local regulatory authorities. (To receive a copy of our EPSS Matrix outlining each step of the commissioning process, go to the bottom of this page.)

During the design phase, the EPCx develops functional testing criteria for the EPSS, ensuring compliance with the intended design. This involves understanding the construction documents, the owner’s project requirements, the EOR’s design rationale, and crucially, the EPSS operation sequence.

Understanding the EPSS operation sequence is vital. It is a detailed plan of actions in response to various scenarios like utility power loss and restoration. While seemingly straightforward, actualizing this plan can be complex, especially with systems that include multiple generators, transfer switches, fuel polishing systems, and load-shedding capabilities.

The construction phase involves developing functional performance tests for the EPSS, considering the EOR’s sequence of operations and specific project requirements. These tests begin with individual component assessments and culminate in comprehensive system performance demonstrations.

Defining “readiness” for testing is crucial to avoid misunderstandings and unnecessary retesting. “Ready for commissioning” criteria for various components – from engine-generators to fuel systems and switchgear – should be clearly established.

The final acceptance phase, or integrated systems tests (IST), involves thorough testing of all EPS components, transfer switches, and electrical distribution. This phase verifies the integration and proper functioning of the entire EPSS during emergencies. Normally this includes the concurrent testing of all Uninterrupted Power Supplies (UPS).

Re-commissioning an existing EPSS with new components has its challenges, but the strategy remains the same: test parts of the system before the whole. The EPCx collaborates closely with the owner and facility manager to ensure successful testing while minimizing disruption to occupied spaces. This process should be completed every 10 years for several reasons, such as vendor support, parts availability, and technology changes.

Overall, successful commissioning hinges on thorough planning and clear expectations based on design criteria, operational sequences, and owner requirements. The commissioning plan should articulate these along with criteria for readiness and integrated system test procedures.

In summary, emergency power systems are classi?ed into legally required systems, Level 1 systems (critical for life and safety), Level 2 systems (less critical), and optional standby systems (not mandated by code but provided for additional emergency power capabilities). This classification is guided by standards such as NFPA 70, 70B, 99, 101,110, and 111 if applicable.

Again, it is of utmost importance that a EPCx have hands on experience with the inspection, maintenance, and testing of Emergency Power Supply Systems. We suggest asking for factory training certificates and references.

EPSS Commissioning Matrix

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