NFPA 70, Article 708, Critical Operations Power Systems (COPS)
for Water and Wastewater Pumping Stations in the state of Missouri

Water and wastewater pumping stations are vital components of any community's public health and safety infrastructure. They are responsible for the essential management of water resources, ensuring that communities have access to clean water for drinking, cooking, and sanitation, and that waste is properly processed and treated. As such they fall under the domain of NFPA 70, Article 708, Critical Operations Power Systems (COPS). The following article is a detailed discussion on their critical role and their need for surge protection.

In the state of Missouri, and in the area around the city of Saint Louis, several agencies are responsible for overseeing water and wastewater pumping stations, they include:

UL508A Industrial Control Panel

The Critical Role of Water and Wastewater Pumping Stations

Water pumping stations play a pivotal role in the delivery of potable water to homes and businesses. They ensure that the water supply meets health and safety standards to prevent waterborne diseases. Conversely, wastewater pumping stations are just as crucial as they manage the effluents and sewage, treating it to prevent contamination of water bodies, which could result in serious health hazards.

In addition, properly functioning wastewater facilities are essential for protecting the environment from untreated sewage discharges, which can cause eutrophication in bodies of water, leading to the destruction of aquatic ecosystems. These facilities are also economic linchpins. Any significant downtime can lead to halted business operations that depend on water, and the costs associated with clean-up or health issues from water contamination can be substantial.

In emergency situations caused by industrial accidents or natural disasters like storms, tornados, floods or fires, water pumping stations ensure the availability of sufficient water and water pressure to aid during active events and/or in the recovery efforts. Wastewater stations are critical components of systems for mitigating the risks of flooding by efficiently managing stormwater, especially in urban areas.

AC Power SPD	AC Power Din Rail SPD	Data Line Din Rail SPD

The Need for Surge Protection

Power surges can be caused by lightning strikes, grid switching, or other electrical anomalies. Without adequate protection, a surge can damage sensitive equipment within the control panels of pumping stations, leading to failures in pumps, monitoring systems, and control mechanisms. Surge Protective Devices (SPDs) are designed to prevent these damages by diverting excess voltage away from the electrical components they protect.

All Water and wastewater pumping stations are equipped with sensitive electronic equipment like programmable logic controllers (PLCs), power supplies and sensors that can cause disruption, degradation or completely destroyed by transient surges.

Surge Protective Devices (SPDs) are essential in safeguarding these systems, ensuring that they remain operational during and after surge events. They protect against voltage spikes that could otherwise result in equipment malfunction, leading to water supply disruption or sewage overflow.

It is important to understand the regulatory compliance requirements with standards like the National Electrical Code (NEC, NFPA 70, Article 708, which classify certain power systems as Critical Operations Power Systems (COPS), is often a legal requirement. It mandates that systems critical to public safety, like water and wastewater facilities, have adequate protection against transients.

A failure in these systems can lead to public health emergencies. For instance, if wastewater systems fail, there is a risk of sewage backing up into homes or flowing into natural waterways, posing severe health risks. While the installation of SPDs represents an upfront cost, the long-term savings from avoiding system downtime, equipment replacement, and potential public health crises make it an economically sound investment. With climate change and increasing weather-related disasters, the importance of resilient public utility systems cannot be overstated. SPDs are an integral part of this resilience, ensuring that water and wastewater facilities can withstand and quickly recover from surge events.

In the context of the UL 508A Standard for Industrial Control Panels, SPDs are important components for the safety and reliability of the control panels that manage this critical infrastructure.

Remote VFD Control Panel

Below is a table summarizing the sections of the UL 508A standards where SPDs are mentioned:

Table 1 - Components that comply with specific requirements

The first step in determining the acceptability of the SPD for a given application or piece of equipment is to consider the UL SPD Type. This is the case for UL 508A as well as all other UL Listed equipment. This first level compliance is based on the UL Approval (LISTED or RECOGNIZED ) of the SPD or UL SPD Type and it’s Suitable Ratings. This means that the SPD has met all safety, performance, environmental and electrical system ratings of the application.

If any of these criteria are not fully met, it will require a Procedure Description, a File Update and/or Additional Testing. These actions will require additional costs that may be substantial. For this reason, it is in the interest of the specifier to use UL LISTED SPD (Type 1 or Type 2) to eliminate any uncertainty or to make sure the UL RECOGNIZED SPD (Type 1CA, Type 2CA, Type 4CA, Type 5) is selected at the initial UL evaluation of the control panel or at the submittal of the equipment to UL for compliance testing.

In conclusion, water and wastewater pumping stations are not just utilities; they are the backbone of public safety and community well-being. Ensuring they are equipped with surge protection is not merely a technical concern but a fundamental aspect of civic responsibility and foresight. As communities continue to grow and face more complex challenges, the robustness of these essential services will be a key determinant in their ability to thrive and maintain public safety.

For more information on the UL 508A Standard for Industrial Control Panels and How To Protect A UL 508A Industrial Control Panels, consult the linked articles for a complete list of application points and recommended Surge Protective Devices (SPD) based on each network and the sensitive critical components that require protection from overvoltages from Lightning, Switching and other electrical events. In addition, if you would like to learn about this subject, request a specific presentation and earn continuing education credits from the IEEE.

Approval Considerations based on UL SPD Type

UL Mark	UL1449 SPD Type	Suitable Ratings	Procedure Described	File Update or Additional Testing	Notes
	1 2	Yes	No	No	The only requirement is that the SPD must match electrical and environmental ratings of the UL 508A Control Panel. A UL field inspection of the control panel with the SPD installed is required as a part of a standard follow-up service visit.
	1CA 2CA 4CA 5	Yes	Yes	Yes	Yes – All UL recognized SPD’s require a UL engineering evaluation of the SPD’s existing UL1449 E–file. This will result, at a minimum, in a cost to update the UL file and may also require testing that would result in additional costs.

CITEL UL LISTED SPD meeting all requirements of UL508A

The following is a list of products for each section. They are UL Listed SPD and require only that they meet the "Suitable Rating" of the control panel. They can be used in all UL locations including,

• Service Equipment Supply Side of Overcurrent Protection
• Service Equipment Load Side of Overcurrent Protection
• Non-Service Equipment Feeder or Branch Circuits
• Isolated Control Circuits

UL508A Paragraph reference	Component description	UL Standard	Category control number(s)	System	Part #	Link
36.4.1 Miscellaneous power devices	Listed Surge Protective Devices	UL 1449	VZCA	120Vac 1-Phase 2W+G Single Phase	DS72US-120S/G
				120-240Vac 1-Phase 2W+G Single Phase	DS72US-240T/NN
				120/240Vac 1-Phase 3W+G Split Phase	DS73US-120T/G
				120/208Vac 3-Phase 4W+G Wye	DS74US-120Y/G
				277/480Vac 3-Phase 4W+G Wye	DS74US-277Y/G
				480Vac 3-Phase 3W+G Delta	DS74US-480D
47.1.1 Surge control devices	Listed Surge Protective Devices	UL 1449	VZCA	120Vac 1-Phase 2W+G Single Phase	DS72US-120S/G
				120-240Vac 1-Phase 2W+G Single Phase	DS72US-240T/NN
				120/240Vac 1-Phase 3W+G Split Phase	DS73US-120T/G
				120/208Vac 3-Phase 4W+G Wye	DS74US-120Y/G
				277/480Vac 3-Phase 4W+G Wye	DS74US-277Y/G
				480Vac 3-Phase 3W+G Delta	DS74US-480D
47.1.3 Surge control devices	Listed isolated Loop Circuit Protectors	UL 497B	QVGQ	RS422	DLA-06D3
				RS232 RS485	DLA-12D3
				4-20mA Current Loop	DLA-24D3
				48Vdc	DLA-48D3
75.8.4 Service Equipment Use	Surge Protective Devices	UL 1449	VZCA	120Vac 1-Phase 2W+G Single Phase	DS72US-120S/G
				120-240Vac 1-Phase 2W+G Single Phase	DS72US-240T/NN
				120/240Vac 1-Phase 3W+G Split Phase	DS73US-120T/G
				120/208Vac 3-Phase 4W+G Wye	DS74US-120Y/G
				277/480Vac 3-Phase 4W+G Wye	DS74US-277Y/G
				480Vac 3-Phase 3W+G Delta	DS74US-480D

For further details, you can visit the Municode Library for St. Louis County and the Wastewater Control Code specifically for more information.

10108 USA Today Way Miramar, FL 33025 USA	Contact us to develop a surge mitigation solution for your application
www.citel.us	Where to purchase Citel SPDs