Yokogawa WTB10-DO Series Dissolved Oxygen Measurement System Terminal Box

Fix the wall mounting bracket (K9141SC) to the wall with 3 M8 screws, and then secure the terminal box to the bracket with 4 M5 screws.

3. Cable entrance opening

The cable entrance at the bottom of the terminal box is a pre designed groove (not opened), which needs to be opened with a tool before wiring: align the tip of a cross screwdriver or other tool with the center of the groove, lightly tap the tool head with a hammer, and break the entrance hole along the groove (the sensor cable entrance and the extension cable entrance need to be opened separately).

Wiring operation specifications

1. Sensor cable connection

Dismantling the terminal box cover: Loosen the 2 screws on the front panel and remove the cover;

Installation of cable sealing sleeve: Remove the nut of JIS A8 grade cable sealing sleeve (B1001JZ) and assemble it to the sensor cable inlet in the order of "nut → gasket → main body → cap", ensuring that the sealing sleeve is in contact with the box body;

Cable insertion: Remove the cap, clamping claw, and rubber gasket from the sealing sleeve, place it on the sensor cable, and insert the front end of the cable into the terminal box;

Wiring: Connect the sensor cable core wires according to the terminal numbers (refer to the correspondence between "core wire color terminal number": brown -16, white -12, black -11, green -14, yellow -15, red -13), ensuring correct and secure wiring;

Sealing fixation: Install the rubber gasket and clamping claw back into the sealing sleeve, tighten the cap to prevent water ingress, and be careful not to overtighten and damage the cable.

2. Extend cable connection (terminal box converter)

Preparation work: The two ends of the extension cable have been pre treated (with no directional difference). If conduit protection is required, the DIN Pg13.5 sealing sleeve at the inlet of the converter sensor cable needs to be replaced with a JIS A15 level sealing sleeve (standard);

Install sealing sleeve/adapter:

No conduit: Install the JIS A15 grade sealing sleeve (B1002JZ) onto the extension cable in the order of "cap → clamping claw → rubber gasket → main body → gasket → nut", and fix the nut after the cable enters the terminal box;

With conduit: Replace the cap of the sealing sleeve with the optional/AWTB (G1/2) or/ANSI (1/2 NPT) adapter, tighten the adapter, and connect the conduit union;

Wiring: Connect the extension cable core wires according to the terminal numbers to ensure consistency with the terminal correspondence of the sensor cable;

Cover the box: After checking the wiring is correct, install the front panel cover back into the terminal box and tighten the screws to ensure sealing.

3. Wiring diagram

WTB10-DO3/- DO4 terminal box: The sensor cable and extension cable are connected to terminals 11 (T1, black), 12 (T2, white), 13 (IE, red), 14 (S, green), 15 (RE, yellow), 16 (SE, brown). The converter (FLXA402/FLXA202/FLXA21) receives signals through the extension cable;

WTB10-DO5 terminal box: only compatible with FLXA402 converter, wiring logic is consistent with - DO3/- DO4, please note that the terminal thread specification is M3 (- DO3 is pin type, - DO4 is M4).

Inspection and maintenance

1. Regular inspection (recommended once a year or every two years, with early inspection in case of abnormalities)

**Moisture inspection * *: Remove the terminal box cover and check if the interior is damp. If it is damp, use a hair dryer to dry it; Several desiccants (silica gel) are saturated with moisture, replace with spare desiccants (30g/part, part number K9020XR);

Corrosion inspection: Check whether the terminals and wires have corroded due to the invasion of corrosive gases. If there is a risk of poor contact or wire breakage, the corroded parts need to be replaced; When replacing the core wire crimping terminal, it is necessary to keep the wiring number label (ribbon) to avoid wiring errors.

2. Maintain parts list

The commonly used maintenance parts for terminal boxes include seals, fasteners, desiccants, etc. Different models correspond to slightly different part numbers. Taking WTB10-DO3 as an example:

Part name, part number, quantity, and purpose

O-ring G9303NB 2 sealing box gap

Desiccant (30g) K9020XR 1 absorbs moisture inside the box

Panel screws (M3 × 4) Y9304LB 2 fix the front panel

Install screws (M5 × 8) Y9508JU 4 to fix the terminal box and bracket

Cable sealing sleeve (JIS A8) B1001JZ 1 sensor cable sealing

Cable sealing sleeve (JIS A15) B1002JZ 1 extension cable sealing

Key precautions

Installation sealing: All cable entrances and box covers must be sealed to prevent rainwater and moisture from entering; When adapting the conduit, the flexible joint should be tightened to avoid cable protection failure;

Wiring specifications: strictly follow the corresponding wiring of "core wire color terminal number", incorrect wiring may cause measurement abnormalities or equipment damage; The length of the extended cable must be consistent with the selection and cannot be cut or spliced arbitrarily;

Environmental protection: Although it is an outdoor type, it is still necessary to avoid long-term exposure to strong corrosion and high humidity environments, and regularly check the condition of desiccants and seals;