Three Phase Non-Continues Unbalanced Dual Element Electric Water Heater Thermostat Wiring
In our today post, we will be showing three phase non-simultaneous and unbalanced electric water heater thermostats and dual heating elements wiring (480V and 400V AC) in electric water heater wiring and installation series.
We already know the difference between balance and unbalance (imbalance) three phase water heater wiring discussed in three phase simultaneous water heater wiring, so we will stick to the three phase non-continuous water heater wiring only.
3-Phase Non-Simultaneous and Unbalanced Water Heater Thermostat Wiring
Non-simultaneous or non-continuous means that only one heating element and related thermostat operates at a time either lower or upper. In other words, the upper and lower thermostats and heating elements are wired such a way where both are dependent on each other. When the upper heating element do their job, the wiring configuration automatically disconnect the upper thermostat as well as heating element and connected the lower thermostat and heating element.
Keep in mind that both the lower and upper thermostats are ECO-protected i.e. both are same. In this wiring connection, the Line 1 (Red) is connected to the upper thermostat terminal L1 and latter L3 terminals of lower thermostat via terminal T4 of upper thermostat. Line 2 (Yellow) is connected to the L3 terminal of upper thermostat and Line 3 (Black) is directly connected to the L1 of lower thermostat.
Upper heating element is connected via T2 and T4 of upper thermostat while the lower heating element is connected to the L4 and T2 terminals of lower thermostat.
The same wiring diagram can be used for three phase 480V AC (US – NEC) or any other three phase supply like 3-Phase 400 – 415 V AC (UK & EU – IEC). Note that we have used red, black and blue for three phase hot lines for illustration purpose only. You may follow your regional electrical codes and wiring colors (see below section).
- How to Wire 120V Simultaneous Water Heater Thermostat?
- How to Wire 120V Non-Simultaneous Water Heater Thermostat?
Circuit Breaker & Wire Size for 3-Phase Water Heater
A 6 gauge wire should be used for each line as this is non-simultaneous wiring (for simultaneous, we have used 6 gauge for each line). You may use the appropriate cable / wire and circuit breaker according to the heater rating. Check the user manual and nameplate data printed on thermostat and heating elements. The following table shows the suitable cable / wire size and fuse / circuit breaker protection size.
- How to Wire Non-Simultaneous 240V Water Heater Thermostat?
- How to Wire 240V Simultaneous Water Heater Thermostat?
3-Phase Wiring Color Codes – IEC & NEC
Three Phase 480 AC:
Black = Phase 1 or Line 1, Red = Line 2, Blue = Line 3, White / Gray = Neutral and Green/Yellow = Earth Conductor
Three Phase 400 – 415 AC:
Grey = Phase 1 or Line 1, Black = Line 2, Brown = Line 3, Blue = Neutral and Green = Earth Conductor.
Related Wiring Installation Tutorials:
- Single Phase Electrical Wiring Installation in Home – NEC & IEC
- Three Phase Electrical Wiring Installation in Home – NEC & IEC
- How to Wire Auto & Manual Changeover & Transfer Switch – (1 & 3 Phase)
- How to Connect a Portable Generator to the Home Supply – 4 Methods
- How to Wire Analog and IP PTZ Camera with DVR and NVR?
- How to Wire Different Fire Alarm Systems – Conventional & Addressable
- Even More Residential Wiring Installation Tutorials