Healthcare facilities consist of many lifesaving equipment that require a continuous supply of power and are normally categorized as critical or essential loads. A power outage for an extended period can cause serious problems. To overcome this issue, proper power system studies according to the standards are performed, so that the occurrence of power loss can be minimized. One of these standards are Electrical Coordination Policy (PIN70) of HCAI. HCAI stands for Health Care Access and Information, formerly known as OSHPD (Office of Statewide Health Planning and Development) is a department of California mainly concerned with the healthcare situation within California.
OSHPD become the HCAI after the signing of 2021-22 Budget and trailer bills by Governor of California Gavin Newsom. The transition from OSHPD to HCAI included certain administrative and policy changes, reallocation of budgets, and creation of new departments. As mentioned on its website, HCAI defines its mission as, to expand equitable access to quality, affordable health care for all Californians through resilient facilities, actionable information, and the health workforce each community needs.
Policy Intent Notice (PIN) is the policy document released by the OSHPD/HACAI on topics pertinent to Occupational Health and Safety Hazards. They are listed in numeric order. The topic of the blog is related to PIN 70 – Electrical Coordination. The PIN 70 is intended to clarify how the HCAI would enforce overcurrent protective device coordination requirements for both new and existing electrical systems.
Electrical coordination involves coordinating the overcurrent protective devices (OCPD) in such a way that outages caused due to the fault remain localized at the place of an overcurrent condition
Figure 1 shows the opening of only circuit breaker ‘F’ if a short circuit occurs at the branch feeding load 5, while circuit breaker A remains closed, thus showing the localization of fault and the circuit breakers being coordinated. The opposite case is illustrated in figure 2.
Figure 1 Example of Coordinated Electrical System
Figure 2 Example of Non-Coordinated Electrical System
The following areas are considered by PIN 70 to be requirements for OCPD coordination as per NFPA 70, National Electrical Code (NEC).:
In order to coordinate the OCPDs, a coordination study is performed. Through that study, the Time-Current Curves (TCC) are achieved that graphically represent the overcurrent operational function of each OCPDs with respect to time. Figures 3 and 4 are showing the TCC curves.
Following are the points of Policy for this PIN
The procedure and requirements to implement the PIN policy of OCPD coordination for the different categories as mentioned earlier will be evaluated by the HCAI plan reviewers to ensure a code-compliant design or installation. However, for a detailed procedure please refer to the website of HCAI as in this blog summarized procedure is provided.
Following are the common points for all categories,
The following are some essential points that are laid by the PIN-70 for the electrical coordination of Essential Electrical Systems.
Figure 6 Essential Electrical System Coordination - Optional Load Branch
The following are some essential points that are laid by the PIN-70 for the electrical coordination of Emergency Systems and Legally Required Standby.
Figure 9 Emergency System Selective Coordination
The following are some essential points that are laid by the PIN-70 for the electrical coordination of Elevators,
Figure 10 Elevator Selective Coordination
The following are some essential points that are laid by the PIN-70 for the electrical coordination of OCPDs of the fire pump used in multibuilding campus-style complexes,
HCAI has laid out some requirements that must be met during the construction. It provides the recommendation to the EEOR for the submission of the final coordination study. If any material changes are required because of the final coordination study, it must be documented and submitted as an Amended Construction Document (ACD) for review by the Office. Similarly, if any changes are made in the values and number of OCPDs, a revised coordination study must be submitted with the electrical plans as an ACD.
In this section, we will explore two examples to understand the application of the HCAI PIN 70 electrical coordination requirement.
Assume an existing equipment branch PANEL PNL1 is fed by 600 amp feeder circuit breaker in which a new 300 amp breaker is added as a feeder breaker to feed new subpanel PANEL PNL2 which has a 300 amp main circuit breaker, eight 10 amp circuit breakers, two 60 amp circuit breakers, and one 100 amp circuit. breaker. The coordination study would need to show coordination between:
Since the new 300 amp circuit breaker in PANEL PNL 1 and the new 300 amp main circuit breaker in PANEL PNL 2 are in series, therefore they are not required to coordinate with each other as per 517.31(G) Exception No. 2. OSHPD will not require coordination study to evaluate circuit breakers above the 600 amp circuit breaker feeding PANEL PNL 1, and it will not require coordination to be evaluated between the 600 amp circuit breaker and the existing circuit breakers in PANEL PNL1.
Consider a situation in which a new 80 amp circuit breaker is being added to an existing critical branch PANEL CL05. PANEL CL05 is fed from a 200 amp feeder breaker. PANEL CL05 has a mix of existing branch circuit breakers ranging in value from 20 amp to 50 amp.
A coordination study is required demonstrating the new 80 amp circuit breaker will coordinate with existing upstream 200 amp feeder breaker since this is the point of connection to the existing essential electrical system. OSHPD will not require a coordination study to evaluate circuit breakers above the 200 amp circuit breaker feeding PANEL CL05, and it will not require coordination to be evaluated between the 200 amp circuit breaker and the existing circuit breakers in PANEL CL05.
HCAI PIN 70 provides the necessary requirements and recommendations that must be met for the achievement of successful selective coordination of OCPDs in different types of systems. PIN 70 also specified the role of EEOR and other concerned personnel in the submission of the final coordination study, and the procedure for the submission of the other documents. The purpose of this blog is to provide an overview and insight of the HCAI PIN 70, however, this blog should not be treated as an alternative to HCAI PIN 70 or material to refer to for implementing a Selective Electrical Coordination.
About The Author
Abdur Rehman is a professional electrical engineer with more than eight years of experience working with equipment from 208V to 115kV in both the Utility and Industrial & Commercial space. He has a particular focus on Power Systems Protection & Engineering Studies.