PTURNS Command

Applies to: ALL modes (general purpose).

The PTURNS (Primary Turns) command sets the number of primary turns. When the primary conductor is wound N times through the hole of the DCCT, the DCCT measures N times the conductor current. This increases the sensitivity to small currents, while the full-scale current of the conductor is divided by N.

The full-scale current depends on the connected DCCT (see DCCT). As an example, with a 200 A DCCT the full-scale current of the conductor is 100 A with two primary turns, and about 66.7 A with three primary turns.

Warning

Do not apply the rated nominal full-scale primary current (for example 600 A for a CT-600) when carrying out multiple turns on the primary conductor hole.

The value N given to the command has to be equal to the number of turns physically applied to the DCCT, so that the CT-BOX divides the readings by the same factor and reports the current flowing in the conductor. The factory-defined number of turns is 1 (no turns applied to the primary conductor).

Note

The number of primary turns is stored in the unit’s flash memory and is retained after a power cycle. Set it back to 1 when the additional turns are removed from the DCCT.

Command Format:

R/W	Command	Response	Description
W	PTURNS:<N>	ACK / NAK:x	Set the number of turns applied to the DCCT
R	PTURNS:?	<N>	Read the configured number of turns

Parameter(s):

Name	Type	Allowed values	Default	Description
<N>	int	1 – 100	1	Number of primary turns

Example(s):

Set the number of turns to 3:

PTURNS:3
ACK

PTURNS:?
3