The relay belongs to the utility, and they are the ones that calibrate it to protect their system. How much leverage does one have getting them to modify their equipment? The device passed calibration, all within 2% of specified values, but it's their specification.
There is no separate neutral...
We are starting to have trouble getting the main to hold in due to a trip on the 50/51 relay on the neutral leg. After closing the main, it tripped when closing 2 out of 4 of the load switches. We d/c'd the load from the transformers supplied by the switches with no change. After several...
I use and specify NFPA 79 (old JIC) format in a US foundry operation. That way I have it consistent to aid in troubleshooting for the maintenance folks. They what sheet and line to look at by the wire number...
In re: the logic, for troubleshooting help I often include a timing chart, event or...
Instead of adding more valves, maybe consider using a N.O. 3-Way "diverter" valve. Instead of dead heading when it shuts off it would divert it back to tank or around the pump. I use the Whitey SS ones with pneumatic actuators on my PU resin systems to keep the fluid moving...
//jh
Although you may be able to find a way to justify exclusion, the incremental cost of keeping someone from opening the door with it energized would seem insignificant.
Also if there ever was an incident, OSHA inspectors often site the General Duty clause, basically covering anything they want...
Thanks for the responses, I'm sorry, I guess I was less than clear about the tower. It is a closed loop system, i.e., just a finned coil with 4" flanged connections that the cooling system water flows through.
The sump is part of a separate spray system that just pumps water from the sump to the...
In a closed loop cooling tower system, is there a "best practices" as far as if the pump should pump from the tower return to the heat exchangers, or pump to the tower and the tower returns through the heat exchangers?
It seems like it shouldn't matter, all components are rated for pressures...