Product Overview

The Bently Nevada 24701-28-05-20-027-01-02 is a specialized proximity probe housing assembly. This unit includes a 2.0 inch standoff adapter for extended reach. The 3300 XL 8mm probe with approvals fits inside the rugged enclosure. A short 0.5 metre cable simplifies wiring in tight spaces. The 24701-28-05-20-027-01-02 comes with one explosion-proof fitting for hazardous areas. Engineers select this model for gas compressors, refineries, and chemical plants.

Technical Specifications

Materials & Construction

The housing body uses 303 stainless steel for excellent corrosion resistance. The probe sleeve uses 304 stainless steel for high mechanical strength. A dome cover screws into the top of the housing body. Threaded ports accept conduit fittings for electrical connections. Multiple O-rings create a reliable environmental seal. A thread seal compound prevents leakage at all threaded joints.

Probe & Cable Details

This assembly contains a 3300 XL 8mm probe with approval option 28. This probe carries multiple agency certifications for hazardous locations. The probe cable length is 0.5 metre (20 inches). This short cable reduces signal loss and installation bulk. A gold-plated ClickLoc connector sits at the cable end. The standoff adapter option (20) adds 2.0 inches to the assembly length. The probe penetration (C dimension) is 2.7 inches (027).

Standoff Adapter Function

The 2.0 inch standoff adapter moves the housing away from the machine case. This feature helps when the mounting surface is very hot. It also allows access to the probe in tight mechanical spaces. The standoff adapter is made of 303 stainless steel. It threads between the housing body and the mounting surface.

Dimensional Limits

The probe part number and serial number are not visible after installation. The maximum total (C + D) dimension is 13.5 inches (34.3 mm). This includes the standoff adapter and probe penetration. The compact design fits machines with limited internal clearance. Always verify internal shaft positions before ordering.

Fittings & Mounting

The fittings option (01) includes two critical components. You receive one 3/4-14 NPT explosion-proof fitting. This fitting meets hazardous area requirements for flame containment. You also receive one 3/4-14 NPT plug for sealing the unused port. The mounting thread option (02) is 3/4-14 NPT. This thread matches standard industrial conduit entries worldwide.

Weight & Physical Data

The typical weight is 1.8 kg (4.1 lb) without fittings. With the standoff adapter and fittings, the weight reaches approximately 1.85 kg. The stainless steel construction adds durability for harsh environments. The dome cover seals securely against dust and moisture ingress. The short 0.5 metre cable reduces bulk for conduit routing.

Installation Guide

Follow these steps to install the Bently Nevada 24701-28-05-20-027-01-02 correctly. First, clean the mounting hole threads on your machine case. Apply thread sealant to the standoff adapter threads. Second, screw the standoff adapter into the machine case. Tighten to 29.5 N·m.

Third, screw the housing body onto the standoff adapter. Ensure the orientation allows access to both threaded ports. Fourth, adjust the probe penetration to the 2.7 inch setting. Use a depth gauge to verify the probe tip position. Set the air gap to 1.27 mm (50 mils) from the shaft surface.

Fifth, tighten the probe sleeve locknut to 39.3 N·m. This locks the probe at the correct depth. Sixth, install the explosion-proof fitting into one threaded port. Install the 3/4-14 NPT plug into the other port. Route the 0.5 metre probe cable through the fitting. Connect the ClickLoc connector to your extension cable. Finally, screw the dome cover onto the housing. Hand-tighten only.

Package Contents

• One Bently Nevada 24701 housing assembly body

• One dome cover with pre-installed O-rings

• One 3300 XL 8mm probe with approvals (option 28)

• One 0.5 metre probe cable with ClickLoc connector

• One 2.0 inch standoff adapter (option 20)

• One 3/4-14 NPT explosion-proof fitting

• One 3/4-14 NPT plug

• One integrated probe sleeve (304 stainless steel)

• One tube of thread seal compound

• Paper installation instruction sheet

Frequently Asked Questions (FAQ)

1. What is the purpose of the standoff adapter on the 24701-28-05-20-027-01-02?
The 2.0 inch standoff adapter moves the housing away from the hot machine case. This protects the electronics and cable from excessive heat. It also provides tool access in tight mechanical spaces.

2. What approvals does the probe option 28 carry for the 24701-28-05-20-027-01-02?
The 3300 XL 8mm probe with option 28 carries CSA, ATEX, and IECEx certifications. These approvals allow installation in Zone 1 and Division 1 hazardous areas. Contact Bently Nevada for the complete certification document package.

3. Can I see the probe serial number after installing the 24701-28-05-20-027-01-02?
No, the probe part number and serial number are not visible after full installation. Record all probe information before mounting the assembly. The standoff adapter and housing block the view of the probe label.

4. Why does this model include an explosion-proof fitting?
The explosion-proof fitting option (01) is required for hazardous area compliance. This fitting contains internal flames if a fault occurs. It also prevents ignition of surrounding gases or dusts.

5. What is the maximum total length of the 24701-28-05-20-027-01-02?
The maximum total (C + D) dimension is 13.5 inches (34.3 mm). This includes the 2.0 inch standoff and 2.7 inch probe penetration. Verify your machine internal clearance before ordering this model.