A "dry" contact is a contact that is not initially connected to a voltage source. It could be stand-alone, such as a pressure switch mounted on a boiler. Or, if the contact is mounted as part of an electrical unit that has a power source, then the "dry" contact has no pre-wired electrical connection to that power source. For example, a magnetic motor starter may have an extra contact that is not connected to the control circuit that starts and stops the motor. However, when the motor starts, the "dry" contact changes state, because the mechanical action of the starter moves the contact. This "dry" contact could then be wired to devices/circuits that are separate/remote from the motor starter circuits. I do not recognize the term "no volt contact" but I suspect that it is the same thing. A specific type of dry contact in the USA is a "form C" contact which is a three wire contact: Normally Open(NO), Normally Closed (NC), and a Common (C).
The Volt
1 volt
For measuring electrical Current the electrical equipment used is Amphere meter. This equipment tells the current flow in the equipment.
http://everything2.com/index.pl?node=electrical%20conductivity I think the above link should answer this question.
One volt is the electric potential required to generate one ampere through one ohm. One volt is the electric potential involved when one ampere generates one watt of power. One volt is one joule per coulomb.
The Volt
No. Is a 6 volt system.
Yes 220 & 240 are considered the same.
12
Voltage
Volt is a measure of electrical pressure.
The unit of electrical potential is the volt. The volt was named for the Italian physicist Alessandro Volta.
1 volt
You can use an insulation rating 5000 volt to run 4160 volt supply.
The volt is a measure of electrical force. It measures joules per coulomb.
A 15 amp 125 volt outlet is a household outlet.
If your 1949 truck is a CHEVY or GMC and it still has the original electrical system, it would be 6 volt, negative ground. If it is a Dodge or a Ford with the oringinal electrical system it would be 6 volt, positive ground.