• The recommended arrangement is to use two valves in dierent locations on the
transformer. This improves oil circulation inside the transformer and prevents the returned
oil from immediately mixing with the next sample.
• Use the same valve for oil intake that has been previously used to take oil samples. This
makes the measurements results of the DGA monitor more comparable with previous
laboratory analysis results. After the oil lines are connected, you will not be able to take oil
samples from the valves. Consider adding a new sampling valve to the intake oil line if you
need to continue taking oil samples.
• Check if the transformer circulates its oil by forced convection. Oil flow inside the
transformer makes the sampled oil more representative of the overall oil volume. It is also
useful if you have to use two valves that are close together, as it carries the returned oil
away from the valve.
• It is possible to use a T-joint to connect both lines to a single valve but the T-joint must be
close to the transformer − no farther than one meter (3 ft) from the valve. If a T-joint is
used, the transformer should be of a type that circulates its oil.
• Check the type of connection thread on the valves, and make sure you have appropriate
adapters for connecting the oil lines to the valves.
• The maximum allowed length of an oil line is 10 m (33 ft).
Some typically available locations of oil connections are presented in Figure 1 (page 17).
OPT100 Installation Guide M211857EN-R
16
To Next Page
Loading...