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Panelboard Testing

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    Panelboard Testing

    Why doesn't NETA specify tests for panelboard assemblies? We do a lot of acceptance testing and there's often language in the scope of work for panelboards where they state something like "complete each inspection and test specified in NETA ATS for panelboards." Engineers copy/pasting scopes that they don't read or understand isn't really new or surprising, but I feel like they can be forgiven for thinking there would be a testing procedure for such a common part of the inside electrical system.

    When we do this type of work we basically test the main breaker per 7.6.1.1, megger the panel bus with the branch CBs open, megger again with the branch CBs closed (so the test includes all the CBs together), & inspect for correct installation, anchorage/alignment, etc. We also exercise each breaker.

    Does anyone else regularly test panelboards? Anyone have insight into why this isn't included in the NETA standards?

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    Quote Originally Posted by anonymous View Post
    Why doesn't NETA specify tests for panelboard assemblies? We do a lot of acceptance testing and there's often language in the scope of work for panelboards where they state something like "complete each inspection and test specified in NETA ATS for panelboards." Engineers copy/pasting scopes that they don't read or understand isn't really new or surprising, but I feel like they can be forgiven for thinking there would be a testing procedure for such a common part of the inside electrical system.

    When we do this type of work we basically test the main breaker per 7.6.1.1, megger the panel bus with the branch CBs open, megger again with the branch CBs closed (so the test includes all the CBs together), & inspect for correct installation, anchorage/alignment, etc. We also exercise each breaker.

    Does anyone else regularly test panelboards? Anyone have insight into why this isn't included in the NETA standards?
    Good question, I often wonder this myself. Not sure why NETA doesn't include this. We basically will do a visual/mechanical inspection then megger of the panel bus and main breaker (important to do open line to load), maybe some DLRO checks on the bus depending on the size. Its always good to do a 2-point ground test to a point in the room. Typically would only primary the main breaker if its say over 400A or called for in the specs. Also good to operate each breaker a couple of times to make sure they open/close properly.

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    I did a little more research in case anyone is interested: ANSI/NEMA PB 1.1 has some info on this (latest version is 2013, but I only have access to the 2007 version).

    Section 7 "Steps to be Taken Before Energizing"

    7.1 ACCESSIBLE ELECTRICAL CONNECTIONS
    Tighten all accessible electrical connections to the manufacturer's torque specifications. If such information is not provided with the equipment, consult the manufacturer.
    7.2 BLOCKS AND PACKING MATERIALS
    Make certain that all blocks and packing materials used for shipment have been removed from all component devices and the panelboard.
    7.3 SWITCHES, CIRCUIT BREAKERS, AND OTHER OPERATING MECHANISMS
    Manually exercise all switches, circuit breakers, and other operating mechanisms to make certain they operate freely.
    Check the integrity of all electrical and mechanical interlocks and padlocking mechanisms. For key interlocked systems, assure that only the required number of keys are accessible to the operator.
    7.4 SHORT CIRCUITS AND GROUND FAULTS
    To make sure that the system is free from short circuits and ground faults, conduct an insulation resistance test phase to ground and phase to phase with the switches or circuit breakers in both the open and closed positions. If the resistance reads less than 1 megohm while testing with the branch circuit devices in the open position, the system may be unsafe and should be investigated. If after investigation and possible correction, low readings are still observed, the manufacturer should be contacted. Some electronic equipment (metering, TVSS, etc.) may be damaged by this testing. Refer to the manufacturers equipment markings for guidelines.
    7.5 GROUND FAULT PROTECTION SYSTEM
    Test the ground fault protection system (if furnished) in accordance with the manufacturer's instructions. See Section 230.95 of the National Electrical Code and NEMA Standards Publication PB 2.2, Application Guide for Ground Fault Protective Devices for Equipment.
    7.6 ADJUSTABLE TIME CURRENT TRIP DEVICE SETTINGS
    Set any adjustable time current trip device settings to the proper values.
    NOTE—Experience has indicated that damage from overcurrent can be reduced if the devices used for overload and short-circuit protection are set to operate instantaneously (that is, without intentional time delay) at 115 percent of the highest value of phase current which is likely to occur as the result of any anticipated motor starting or welding currents.
    7.7 GROUNDING CONNECTIONS
    Check to determine that all grounding connections are properly made. If the panelboard is used as service equipment, make certain that the neutral, if present, is properly bonded to the cabinet.
    7.8 FOREIGN MATERIAL
    Remove all foreign material from the panelboard and cabinet before installing the cabinet front. Make certain that all deadfront shields are properly aligned and tightened. Install the cabinet front in accordance with Section 8.
    There's also a section 10 on maintenance but it's a little longer so I won't post it. NFPA 70B doesn't seem to have anything on panelboard assemblies (chapter 13 "molded-case circuit breaker power panels" is all about breakers, not panels).

    I thought maybe the reason NETA didn't specify procedures was that there weren't any other standards specifying how to do the tests (since per the preface to NETA ATS, "it is not intended that this document list how to test specific pieces of equipment or systems." As in: NETA tells you which tests to do, other standards tell you how to do them). But since NEMA PB 1.1 is pretty straightforward as to what needs to be done, I don't get it. NETA should probably add a section on panelboards.

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    Quote Originally Posted by anonymous View Post
    I did a little more research in case anyone is interested: ANSI/NEMA PB 1.1 has some info on this (latest version is 2013, but I only have access to the 2007 version).

    Section 7 "Steps to be Taken Before Energizing"



    There's also a section 10 on maintenance but it's a little longer so I won't post it. NFPA 70B doesn't seem to have anything on panelboard assemblies (chapter 13 "molded-case circuit breaker power panels" is all about breakers, not panels).

    I thought maybe the reason NETA didn't specify procedures was that there weren't any other standards specifying how to do the tests (since per the preface to NETA ATS, "it is not intended that this document list how to test specific pieces of equipment or systems." As in: NETA tells you which tests to do, other standards tell you how to do them). But since NEMA PB 1.1 is pretty straightforward as to what needs to be done, I don't get it. NETA should probably add a section on panelboards.
    Here is version 2013:

    https://library.industrialsolutions....ATERMARKED.pdf

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