Load
Thetford C223-CS flush-control connections
Identify the toilet's dry-contact pump control and review its separate power requirements. Select the pump and both protected supplies from the installation manuals before adding a powered circuit.
- Nominal voltage
- 12 V
- Compatible systems
- 12 V
Connection overview
Flush-control view for the C223-CS.
COM and NO are dry contacts for the external pump control. They do not supply pump power; the toilet and pump need separately designed protected feeds.
Installation notes
Before you install.
Open a question for model-specific guidance and sources.
Verified against the manufacturer's documentation (rev. C220-series installation manual, manufacturer download January 2025), checked 2026-10-01. Manufacturer documentation →
Which C220 variant is covered?
The C223-CS cassette toilet flushes from the vehicle's water system. Do not substitute the C222 variant's integrated flush-water arrangements. The C220 installation manual covers several variants, so follow the columns and drawings marked for the C223-CS throughout. The fresh-water pump is a separate electrical load, even when the toilet operates its control relay.
What are the electrical connections?
The electrical drawing, page 23, specifies a 10–15 V supply capable of delivering 3 A. This is a source-capability requirement, not a measured continuous current; the catalog therefore leaves actual operating current and surge unset. Red is supply positive and black is return, shown as positions 5A and 5B in the manual's connector drawing.
The separate grey and purple wires are the external pump-relay contacts: grey NO at 4A and purple COM at 4B. Their maximum contact load is 6 A. They are shown as control terminals in the catalog, not as another battery input, and the model does not simulate the relay's switching. Do not place a pump whose load exceeds that rating directly through these contacts.
How should the supply and pump be planned?
The manual identifies the red/black harness as 0.5 mm² and grey/purple as 0.75 mm². Those are the appliance's harness sizes, not an unconditional prescription for a long battery run. The reviewed page does not state an external branch-fuse rating. Protect each installation feed for its conductor and equipment requirements and account separately for the pump's startup and operating demand. The 3 A catalog power-terminal boundary represents the stated supply capability; it is not a verified connector ampacity.
What must be accessible and tested?
Use the installation sequence and final checks, pages 24–25, to verify access to the waste cassette, the service door, the water connection and the electrical connector. Test flushing, the waste-level indication, leaks and unobstructed removal and insertion of the waste tank. Seal the exterior service-door installation correctly and confirm winter draining for the complete water system. If flushing fails, check supply at the toilet, the pump circuit and relay wiring separately rather than treating the toilet and pump as one load.
Fit check
Connect it to the rest of your system.
Describe your setup to draft a system with C223-CS connected. Review the selected parts and cable lengths, then edit the diagram in Crimp.
The model only picks parts and draws the connections. Every wire size and fuse rating still comes from Crimp's own sizing, never from the model.
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Technical reference
Specifications and terminal map.
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Catalog specification
Cassette toilet supplied from the vehicle fresh-water system. The manual requires a 10–15 V source capable of 3 A; it does not specify actual operating current. Separate grey/purple flush-pump relay contacts are limited to 6 A. The pump is a separate load. The 3 A power-terminal value is a source-capability planning boundary.
- Nominal voltage
- 12 V
- Compatible systems
- 12 V
Terminal map
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
+
positive · input
−
negative · input
Pump relay COM
signal · input
Pump relay NO
signal · input
Sources and sizing method
Equipment specifications. Model details, ratings and terminal roles come from the catalog. Check your unit’s label and current manufacturer documentation for its exact revision.
Connection overview. This diagram explains the connection arrangement; it does not calculate cable sizes or protection for the installation. Follow the manufacturer’s complete wiring and protection instructions.
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Plan your installation with C223-CS.
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