SwitChek Frequently Asked Questions

It is the only device that offers:
– Fail safe, continuous indication of isolation. Needed before and during maintenance.
– Positive, continuous indication of switch open to close transition. Needed during maintenance.
– Self testing function. Both automatic and operator initiated.
– Suits field isolator applications. Works with energised or de-energised line sides of the isolation switch. No fuses needed.

No. SwitChek does not replace legally required electrical testing procedures.
Many jurisdictions require electricians to verify de-energisation using approved electrical testing methods before performing electrical work.
SwitChek is intended primarily to support electrical isolation verification for non-electrical maintenance activities.

Refer to the comparison table below for a detailed comparison of verification of electrical isolation / isolator checking approaches.

SwitChek can be installed with minimal switchboard modification and without adding power system fuses.
Installation involves:
1. Mounting the Human Machine Interface (HMI) in a 22.5 mm panel hole.
2. Clipping the electronics and star interface module onto DIN rail.
3. Plugging in the HMI cable between the HMI and electronics module.
4. Connecting the sensing conductors from the star interface to the power conductors.
5. Connecting a 24 VDC earth-referenced power supply to the electronics module.
Many customers report total installation times of approximately 45 minutes, including MCC isolation procedures.

SwitChek requires power to positively indicate a verified switch opened condition. Many installations already have a nearby control power supply that can be used for this purpose.
Where no auxiliary supply exists, some customers use a small DC UPS system or two 12VDC batteries (suitably vented) and battery charger. For example, a 24 VDC UPS with approximately 0.8 Ah capacity may provide:
Approximately two hours of operation for one SwitChek unit.
Approximately one hour of operation for two SwitChek units.
Actual operating times depend on battery condition. SwitChek consumes approximately 2.4 W

SwitChek instrument wiring may be connected to power conductors where the installation complies with the applicable wiring rules eg AS/NZS 3000. Typical requirements include:
– Circuit length less than 3 m.
– No branch circuits.
– Mechanically protected wiring.
– Not installed near flammable materials.
Conductor termination options include:
– Bootlace pins, ring terminals or lugs on small flexible conductors.
– Cable-tied, lip blade terminals on large conductors or busbars.

Potentially, although the impact is generally small.
The SwitChek HMI requires a penetration of approximately 25mm to accommodate a standard 22.5 mm diameter pilot lamp.
Compared with solutions requiring multiple indicators or large viewing windows, the required penetration is relatively modest.
The suitability of any penetration should be assessed against the switchboard design and applicable fault containment requirements.

SwitChek and DeadEasy are designed for different applications.
SwitChek can verify an isolation whether the line side of the switch is energised or de-energised.
This makes it particularly suitable for field isolation switches where the line side is often de-energised.
DeadEasy requires an energised line side and is therefore most suitable for Motor Control Centres (MCCs) and Switchboards.

Firstly, SwitChek 3 phase Isolation Switch Tester is designed to withstand overvoltages sometimes experienced on power circuits. The method for achieving this performance is by the use of sufficient creepage and clearance distances as well as using componentry certified to provide this level of protection.
Secondly, should an internal fault develop within SwitChek, the SwitChek Interface incorporates PPTC resettable fuses which will prevent an arc fault and severe SwitChek damage.
Thirdly, SwitChek is contained in a double insulated, fire retardant, polycarbonate dust proof and water proof (IP66) enclosure. It is mechanically robust.

No specific regulatory approval exists.
In many jurisdictions, regulations require an effective means of verification but do not prescribe a specific technology.
This allows plant operators to select verification methods that are appropriate for their equipment, operating environment and risk profile.
Because regulations are often performance-based rather than prescriptive, formal endorsement by regulators is generally unnecessary.
Ultimately, responsibility for selecting an effective verification method remains with the plant operator.

SwitChek is designed to the requirements of UL 61010-1 but is not currently UL Certified.
In accordance with UL 61010-1 it provides:
– CAT III, 300 VAC Line-to-Neutral (424 VAC Line-to-Line equivalent)

No. The test voltage generated is floating with respect to earth. The voltage is applied across the switch. The test voltage is applied line side with respect to load side. However if a worker was in direct contact with the wires and earth downstream of the isolation switch that incorporates SwitChek, and the AC supply system has an earth reference (common arrangement), the worker would receive a shock current of < 0.5mA for 0.1 second every 30 seconds which for most people is well below their threshold of perception.

SwitChek incorporates self-testing and fault-detection principles designed to prevent unsafe indications.
SwitChek has undergone extensive laboratory, field testing and industry use since 2003.
A Failure Modes and Effects Analysis (FMEA) concluded that:
– A single fault will not prevent the safety function from operating.
– Faults are detected and indicated to the operator.
– The device will not falsely indicate an isolated condition when the circuit remains closed.
For users familiar with functional safety standards, SwitChek 34 has been assessed as:
– ISO 13849-1, Category 3, Performance Level d (PL d)
MTTFd: High, DCavg: Medium, CCF: Pass, Structure = Cat 3
Alternatively, If you are familiar with Functional Safety eg IEC 61508 the following SwitChek 34 information may be of benefit: