ISOM cores measurement
ISOM toroidal accessories enable the location of insulation faults by feeder on extended IT networks, in…
ISOM torus accessories are ferromagnetic location tori designed for ISOM and ISOM Digiware systems. They allow insulation-fault searching per outgoing circuit using OhmScanner technology, in conjunction with a portable ISOM FP-60 locator or a fixed ISOM Digiware F-60 module. These tori meet the requirements of the IEC 61557-9 standard and integrate into extensive IT networks with no need for selective circuit shutdown.
Operating principle of ISOM location tori
OhmScanner technology and per-circuit detection
OhmScanner technology injects a characteristic signal onto the faulty outgoing circuit. The ferromagnetic torus, positioned around the live conductors, detects this signal and precisely identifies the circuit concerned. Our installation experience confirms that this approach eliminates the traditional successive-shutdown method, a source of major operational disruption.
Compatibility with ISOM FP-60 and F-60 locators
The tori communicate equally well with the portable ISOM FP-60 locator for maintenance interventions, or with the fixed ISOM Digiware F-60 module for permanent supervision. This duality offers design offices valuable architectural flexibility depending on the installation's criticality level.
Physical construction and panel integration
Materials and robustness of ISOM tori
The torus itself uses a ferromagnetic material optimised for low-frequency sensitivity. The polyamide housing provides satisfactory mechanical strength in standard electrical panel environments. In the field, we find that this construction withstands the usual thermal and vibrational stresses of tertiary and industrial panels.
Positioning and wiring on protected outgoing circuits
The torus is installed on each outgoing circuit to be monitored, downstream of the circuit breaker or head switch-disconnector. Our commissioning tests show that respecting the conductor direction and fully closing the magnetic circuit directly determine detection reliability.
Typical applications and operational gains
Fault location on extensive IT networks with no shutdown
On hospital, data-centre or industrial IT networks requiring absolute continuity of service, ISOM torus accessories drastically reduce fault-search time. Our installation feedback shows that intervention time typically drops from several hours to a few minutes, with no interruption to healthy circuits.
Distinction from simple centralised monitoring
Unlike a central insulation-fault relay, which signals the existence of a fault without locating it, ISOM tori allow discrimination per outgoing circuit. This distinction proves decisive when the network has several dozen circuits supplying distributed critical loads.
Frequently asked questions
Can an ISOM torus be retrofitted onto an existing installation?
Adding one is technically possible provided a compatible ISOM FP-60 or F-60 locator is available, and each outgoing circuit to be monitored is accessible for fitting the torus. Implementation requires no change to the IT network's topology.
What is the maximum distance between the torus and its locator?
The technical documentation for ISOM and ISOM Digiware systems states the admissible cable lengths between tori and processing modules. Feedback from installers confirms that common distances in panels and technical galleries remain within the functional range with no amplifier.
Does the IEC 61557-9 standard require periodic calibration of the tori?
The standard defines performance requirements and type tests, but does not prescribe a specific periodic recalibration procedure for tori. We nonetheless recommend a functional check during preventive maintenance contracts, by simulating a controlled fault on a dedicated outgoing circuit.