The EA402 913-402-000-012 extension cable carries the low-level eddy current signal between a TQ402 proximity probe and the VM600 signal conditioner. On a clean bench, most cables pass simple continuity. In the field, shielding, grounding, cable routing, and connector condition decide whether the Vibro-Meter VM600 system reports stable vibration data or trips on electrical noise.
This guide covers the shielding and signal integrity practices that help keep EA402 913-402-000-012 installations reliable in industrial environments.
Where EA402 913-402-000-012 Sits in the VM600 Signal Chain
The EA402 913-402-000-012 is a factory-terminated extension cable matched to the TQ402 eddy current probe and the IQS450 signal conditioner. It carries the probe drive voltage, gap voltage, and return path in a single shielded construction.
In a typical VM600 rack, the signal path is:
TQ402 probe → EA402 extension cable → IQS450 signal conditioner → IOC4T communication card → CPUM processor.
Because the gap voltage signal is small and the cable capacitance directly affects the probe system calibration, any shield break, incorrect grounding, or parallel power run can cause false vibration, unstable gap voltage, or intermittent trips.
Shielding Design Rules for EA402 913-402-000-012
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Keep the shield continuous from the probe junction to the rack termination. Do not splice the shield mid-run. A broken shield turns the cable into an antenna.
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Ground at one point only. In most VM600 installations, connect the EA402 shield or drain wire to the IQS450/rack earth at the signal conditioner end. Leave the TQ402/field end floating.
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Keep the drain wire pigtail as short as possible. If the connector requires a pigtail, 50 mm or less is preferred. Long pigtails increase inductance and reduce high-frequency shielding.
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Use the original connector shell and maintain 360° shield contact. A loose connector body, missing backshell, or damaged thread can open the shield even if the center pin is still engaged.
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Do not replace the EA402 with generic instrument cable. The factory cable has controlled capacitance and impedance. A substitute cable changes the probe calibration and can shift the gap voltage.
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Select the correct factory length. EA402 913-402-000-012 and 913-402-000-013 correspond to different standard length codes. Do not connect two EA402 cables in series to extend a run.
Signal Integrity Tips for Field Installation
Routing
- Keep the EA402 at least 200–300 mm away from VFD output cables, motor leads, contactor wiring, and high-current AC circuits.
- Cross power cables at 90° when separation cannot be maintained.
- Do not run the EA402 in the same conduit or cable tray as unshielded power conductors.
- Use metallic conduit or covered cable tray as an additional screen only when the conduit can be grounded correctly.
Mechanical Handling
- Do not pull the EA402 by the connector. Pull only by the cable body with steady force.
- Respect the minimum bend radius. Tight bends damage the braided shield and change cable capacitance.
- Use cable ties with low pressure or hook-and-loop wraps. Crushing the jacket can deform the shield around the inner conductor.
- Leave enough slack near the probe and conditioner so the connector is not under mechanical tension.
- Avoid hanging tools, tags, or other objects from the EA402 cable.
Grounding at the Panel
- Bring the EA402 shield directly to the control cabinet earth bar through a short, direct path.
- Remove paint, rust, and corrosion from the ground lug. Use star washers and torque the fastener correctly.
- Keep the shield ground point close to the IQS450 or VM600 rack ground, not on a distant or painted frame.
- Confirm that the panel earth and the machine frame are not producing a second ground path through the cable route.
Signal Checks After Installation
- At commissioning, record the gap voltage and vibration signal with the machine stopped and running.
- If the gap voltage is unstable or the signal contains 50/60 Hz components, inspect the shield and grounding before changing the probe or conditioner.
- Compare an identical channel with a known-good EA402 if one channel behaves differently.
- Re-verify the signal after any nearby electrical work, motor drive replacement, or cable routing change.
Common EA402 Shielding Problems and Field Fixes
| Symptom | Likely Cause | Field Action |
|---|---|---|
| Erratic gap voltage on one channel | Shield open at connector or drain wire break | Re-terminate or replace the EA402; verify connector shell tightness |
| 50/60 Hz noise on vibration signal | Cable running parallel to power cables or double-ended grounding | Reroute the EA402 away from power; confirm only one ground point |
| High-frequency noise bursts | Long shield pigtail, loose backshell, or poor 360° termination | Shorten the pigtail; tighten the connector; restore full shield contact |
| Signal drifts after temperature change | Damaged insulation, moisture ingress, or cable capacitance shift | Dry the connector if wet; replace the EA402 if insulation is cracked |
| Intermittent trip with no machine fault | Loose connector, broken shield under flexing, or crushed jacket | Inspect every connector joint and cable bend; replace damaged cable |
| Gap voltage offset after cable replacement | Wrong cable type or EA402 length incompatible with probe system | Verify part number 913-402-000-012 and length code before installation |
EA402 913-402-000-012 Installation Checklist
- Confirm the EA402 part number and length code match the installation drawing.
- Inspect connectors for bent pins, oxidation, and missing sealing gasket.
- Route the cable before connecting it; maintain separation from power wiring.
- Connect the shield to the signal conditioner/rack ground only.
- Keep the shield drain pigtail short.
- Tighten connector bodies; do not over-torque plastic or fine-pitch threads.
- Strain-relieve the cable near both ends.
- Power the VM600 rack and verify gap voltage is stable and within the expected range.
- Mark the cable with channel number and installation date.
- Record a baseline signal and compare after one week and after any nearby electrical work.
When to Replace Instead of Repairing
Replace the EA402 913-402-000-012 if:
- The shield has visible cuts, kinks, or flattened sections.
- The connector body is cracked, corroded, or no longer locks.
- Moisture has entered the cable or connector.
- Signal checks fail after re-termination.
- The cable has been pulled beyond its bend radius or tangled with power cables.
- The shield drain wire is broken and cannot be restored without changing the factory termination.
A failed EA402 cable is usually cheaper to replace than a false trip or a missed vibration fault. Always replace with the same part number and length code.
EA402 913-402-000-012 Sourcing and Replacement Support
Joyoung International Trading Co., Limited supplies EA402 extension cables and related VM600 system modules, including TQ402 probes, IQS450 signal conditioners, IOC4T communication cards, MPC4 protection cards, and CPUM processors. We support customers with part number verification, length code selection, and urgent replacement for industrial vibration monitoring systems.
For stock verification, compatibility checks, or fast dispatch:
Email: [email protected]
Phone: +86-181-5013-7565
FAQ
Can I use a standard twisted-pair cable if the EA402 length is not enough?
No. Generic cable changes the probe system capacitance, impedance, and shield performance. Use the correct EA402 factory length instead of adding a field-made extension.
Should the EA402 shield be grounded at both ends?
Usually no. In standard VM600 installations, ground the shield at the IQS450/rack end only. Double-ended grounding can create ground-loop noise unless a verified equipotential high-frequency bonding network is used.
What does the 913-402-000-012 suffix mean?
The suffix identifies the EA402 factory configuration and length code. Select 012 or 013 according to the required cable run. Do not join two EA402 cables to simulate a longer factory cable.
How can I tell if an EA402 shield is damaged before it fails completely?
Look for erratic gap voltage, noise synchronized with motor starts or contactor operation, visible jacket damage, crushed sections, moisture inside the connector, or loose connector bodies.
Do I need to recalibrate after replacing the EA402?
Always verify the gap voltage and system signal after replacing the extension cable. A new cable with the same part number should not require full system recalibration, but the channel must be checked before returning to protection service.
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