Benjo,
"The absence of Earth" prevents shock, but it also prevents a large enough ground current from flowing back to transformer and causing the circuit breaker to trip. This is really the main reason that ground wires were invented in the first place. Otherwise it would have made sense to leave all voltages "floating" relative to ground, as they were in the early electical systems in 1890.
Lack of a ground on a DC system is a clear violation of the US National Electrical Code, Article 250-22, Exception.
Article 250-3 seems to offer an exception for "a rectifier derived DC system supplied from an AC system complying with Secton 250-5", BUT Article 250-5(b)(1) makes it clear that where the system can be grounded so that the voltage does not exceed 150 volts on the ungrounded conductor, then a ground IS STILL required.
I know you are not in the US, so your codes may be different.
"The absence of Earth" prevents shock, but it also prevents a large enough ground current from flowing back to transformer and causing the circuit breaker to trip. This is really the main reason that ground wires were invented in the first place. Otherwise it would have made sense to leave all voltages "floating" relative to ground, as they were in the early electical systems in 1890.
Lack of a ground on a DC system is a clear violation of the US National Electrical Code, Article 250-22, Exception.
NEC Figure 250-6 Note: For an on-premises generator [or DC power source] a grounding connection is required and is to be located at the source of the first system disconnecting means.
Article 250-3 seems to offer an exception for "a rectifier derived DC system supplied from an AC system complying with Secton 250-5", BUT Article 250-5(b)(1) makes it clear that where the system can be grounded so that the voltage does not exceed 150 volts on the ungrounded conductor, then a ground IS STILL required.
I know you are not in the US, so your codes may be different.
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