Fan Monitoring
The power controllers with fans (type designation that includes "F") are fitted with
thermal monitoring. The temperature is measured on the heat sink. In case of a
temperature overrange, a fault indication
Unit overtemperature
is issued.
By default, the device will be switched off and the
FAULT
LED will be lit.
☞
Important
When using the device under UL conditions, this feature must be switched on.
Load Resistance Monitoring
Changes in load resistance can be caused by temperature changes or by aging. There
are two ways to monitor these resistance changes. Absolute monitoring is useful for
loads which do not change over time. Relative monitoring is useful if the resistance
value of the load slowly changes.
Use absolute monitoring for heating elements with R
warm
/R
cold
≈ 1, and use relative
monitoring for heating elements with R
warm
/R
cold
≠ 1.
Absolute Value Load Resistance Monitoring
Absolute value monitoring lends itself to one or more load resistances organized in
parallel or in series. Generally, the effective load resistance value measured is
continuously compared with a configurable absolute resistance minimum and
maximum limit. If these limits are undercut or exceeded, an indication occurs after a
configurable number of mains periods. Using the upper resistance limit, in case of
resistor elements connected in parallel, it is possible to detect a partial load
interruption. Using the lower resistance limit, in case of resistors connected in series,
it is possible to detect short-circuiting of an element.
Relative Value Load Resistance Monitoring
Relative monitoring is useful if the resistance value of the load slowly changes. The
load resistance is measured and compared period to period. A fault is generated if the
change is greater than the configured % change limit. The unit establishes a new
nominal resistance value after each startup, restart, or mains outage.
MAINS LOAD OPTIMIZATION WITH dASM
The digital and dynamic dASM process offers the option of dynamic mains load
optimization when multiple Thyro-PX power controllers operate in the TAKT mode.
For systems in which there are multiple power controllers, individual power
controllers are synchronized so that a regular mains load is achieved. This avoids
random load peaks caused by multiple power controllers switching on at the same
time. The upstream transformer and/or the upstream feed point can be designed for a
Advanced Energy
®
Thyro-PX® Power Controller
57010148-00B
Installation, Setup, and Operation
5‑38