Pentair 920 Series Installation, Operating And Maintenance Instructions page 25

INDUSTRIAL HEAT TRACING SOLUTIONS
Important:
• If an alternate voltage source is selected, then all voltage alarming features are disabled for
this HTC and the VOLTAGE TURNS RATIO is not used.
• It is not possible to set both points to use the others' voltage source.
3.5.20 fIxed voLtaGe settInG (v3.11 and up)
(Only if VOLTAGE SOURCE = FIXED)
purpose: This parameter specifies the voltage value that the HTC should use when the VOLTAGE
SOURCE = FIXED.
range: 0 to 1000 Volts
procedure: Adjust the FIXED VOLTAGE setting to the desired level.
Important: All voltage alarming features are disabled for this HTC and the VOLTAGE TURNS
RATIO is not used when the VOLTAGE SOURCE is set to FIXED.
3.5.21 voLtaGe turns ratIo adJustment
purpose: The VOLTAGE TURNS RATIO adjusts voltage readings for applications where a controller
is switching a load through a step-up or step-down transformer, or is being powered from a source
with a different voltage level than the trace voltage.
range: 0.10 to 9.90 (TO 1)
procedure: Adjust the VOLTAGE TURNS RATIO to equal the ratio of the circuit voltage to the
controller input voltage. Compare the indicated voltage to the measured voltage after setting the
turns ratio and adjust until the two readings are as close as possible.
e.g.: Heating Circuit Voltage:
Module Input Voltage:
VOLTAGE TURNS RATIO Setting:
Important:
• When the VOLTAGE TURNS RATIO has been set appropriately, the HTC will calculate the circuit
power using the adjusted current and voltage readings. Voltage alarms also use the adjusted
circuit voltages.
• The VOLTAGE TURNS RATIO is not used if the selected VOLTAGE SOURCE is not from the
dedicated switch interface.
3.5.22 Current turns ratIo adJustment
purpose: The CURRENT TURNS RATIO adjusts current readings for applications where a
controller is monitoring a load through an external step-up or step-down current transformer.
range: 0.10 to 60.00 (TO 1)
procedure: Adjust the CURRENT TURNS RATIO to equal the ratio of the primary to secondary
windings of the external current transformer. Compare the indicated current to the measured
current after setting of the CURRENT TURNS RATIO and adjust until the two readings are as close
as possible.
Important: When the CURRENT TURNS RATIO has been set appropriately, the HTC will calculate
the circuit power using the adjusted current and voltage readings. Current alarms, as well as the
switch and circuit breaker limiting functions, also use the adjusted circuit currents.
3.5.23 autoCyCLe enabLInG
purpose: The autocycle function momentarily (approximately 10 seconds) applies power to the
heating circuit at the selected interval. It is used to test the integrity of the heating circuit. Alarms
present at the time of autocycle then become latched and remain active after the completion of
the autocycle function. Auto-cycling effectively eliminates the need for preventive maintenance by
automatically verifying the heating circuit integrity.
setting: ENABLE or DISABLE
Procedure: Enable or disable the auto-cycling feature as desired. If the feature is disabled, you will
not be prompted to enter the AUTOCYCLE INTERVAL or AUTOCYCLE UNITS.
EN- Raychem920series-IM-H56874 05/15
480 Volts
120 Volts
4.00
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