The temporary solution we put in place appears to have been effective
But I would not recommend re-enabling panel HMD until the pipe run is restored to watertight integrity on the roof.
We can bypass it and restore power as needed.
What remains to be determined is the integrity now of panel HMD more specifically if we can reuse the main breaker, HVAC 70a breakers and the quality of the bus.
This is 480 V distribution and not rated for wet use.
A lot of those parts have had rusty water soaking them.
Passive components are made up of the structural metal framework and current-carrying bus structures, while active components consist of circuit breakers and fusible devices. The passive parts of the system usually can be cleaned, tested, and reused; active components should be either replaced or evaluated
2.2.1. Insulation resistance test.- A megohmmeter may be used to make tests between phases of opposite polarity and from current-carrying parts of the circuit breaker to ground. A test should also be made between the line and load terminals with the breaker in the open position. Load and line conductors should be disconnected from the breaker under insulation resistance tests to prevent test mesurements from also showing resistance of the attached circuit. Resistance values below 1 megohm are considered unsafe and the breaker should be inspected for possible contamination on its surfaces.
2.2.2. Millivolt drop test.- A millivoltdrop test can disclose several abnormal conditions inside a breaker such as eroded contacts, contaminated contacts, or loose internal connections. The millivolt drop test should be made at a nominal direct-current voltage at 50 amperes or 100 amperes for large breakers, and at or below rating for smaller breakers. The millivolt drop is compared against manufacturer's data for the breaker being tested.
2.2.3. Connections test.- The connections to the circuit breaker should be inspected to determine that a good joint is present and that overheating is not occurring. If overheating is indicated by discoloration or signs of arcing, the connections should be removed and the connecting surfaces cleaned.
2.2.4. Overload tripping test.- The proper action of the overload tripping components of the circuit breaker can be verified by applying 300 percent of the breaker rated continuous current to each pole. The significant part of this test is the automatic opening of the circuit breaker and not tripping times as these can be greatly affected by ambient conditions and test conditions.
2.2.5. Mechanical operation.- The mechanical operation of the breaker should be checked by turning the breaker on and off several times.
As shown in the photos there is plenty of room in the HD distribution panel just left of HMD.
I would recommend the following
First contact Eaton Cutler Hammer to for recommendations if we can just dry out the molded case CBs, megger them across the poles, possibly give them a high current test, and if we can continue to use the buss and enclosure.
Otherwise, if the panel and/or CBs are to be condemned, we can move the two HVAC to panel HD just to the left , which has adequate capacity. They were the only two breakers in 42 circuit panel HMD. The main use for panel HMD is to have a dedicated HVAC panel. It was very lightly loaded.
We will splice the wires that lead to HVAC units one & two from the newly abandoned "panel HMD", (now "enclosure HMD") and move those 2 loads over to their source panel HD.
We then power up the two units. The contractor can fix the leak when he comes back. The question is whether those (2)70 amp HVAC breakers and the 125A main are still okay to use or if we will need to replace them. I would say to replace them.
Also there would be a cost for six Polaris connectors on these number two wires here too and a little bit of wire to swing them over to panel HD.
Some engineers recommend that the "replacement of switchgear should allow only bottom entry of electrical raceways. This will prevent openings into the top of the gear that can allow pathways for water to enter. All conduits entering the gear should be sealed with non-hardening electrical putty having a chemical compatibility with the insulation on the electrical conductors. This will limit moist air from again entering the new equipment. "
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