How to wire Intermatic T1906 and T1976 240volt (208-277 volt)

and T1905 and T1975 120volt

Back to all box-type water heater timersT1900 series at ESO

Larger image T1905-6T1906 manual

T1905 manualWG730 clock motor 125VoltWG1600 clock motor 125Volt

Power consumption: Max 5 watts/ 45Kwh per year

Large image T1975-6With day skipper

T1976 manualT1975 manual

WG733 clock motor 208-277VoltWG1603 clock motor 208-277Volt

Same wiring applies to both T1906 timer and T1976 timerSame wiring applies to both T1905 timer and T1975 timer

Only difference between these two timers is the day skipper wheel on T1976 and T1975

Troubleshoot Intermatic timersIntermatic trippers and parts

Convert 120volt timer to 240V by changing clock motor.WG733 clock motor 208-277VoltWG730 clock motor 125VoltWG736-14 clock motor 480VoltHow to replace Intermatic clock motorMotors at ESOAt Aplus

Normally Open turns on with timer settingsNormally Closed turns off with timer settings

156T1950A tripper / 12 per pkg1900 series timer uses 156T1950A tripperTo operate T1900 series timer, insert tripper into slot.Each tripper represents 15 minutes.Two trippers represent 30 minutes

How to set timer:Insert trippers into dial. Push tripper fully down. Each tripper represents 15 minutes. Standard package arrives with 12 trippers. Insert 12 trippers in a row represents 3 hours. Insert 4 trippers in a row represents 1 hour.Trippers push on-off lever. The on-off lever opens and closes electrical contacts that send power alternately to NO terminal or to NC terminal.Either the NO terminal has power -or- the NC terminal has power. One terminal or the other terminal is ON at all times, and when one terminal is ON the other is OFF.To set time: Rotate dial until current time lines up with stationary silver pointer or timer arrow.Use manual override lever to reverse on-off operation. Timing sequence resumes at next tripper.Remove all trippers to override timer operation.

Check label on side of tank for voltage of water heater

240Volt

T1906 and T1976 control 240Volt water heater

Same wiring applies to 208 thru 240VoltNO terminal is normally open. NO turns 'on' with timer settings. This terminal used for water heater circuit shown on left.NC terminal is normally closed. NC turns 'off' with timer settings.

Use 10 gauge wire for water heater circuit.See basic water heater circuits

Timer is SPST, which means single pole, single throw. Only one Hot wire to water heater is turned off.Suggested wiring that Black Hot wire connect to Black wire at water heater.How to wire water heater thermostats

T1906 manualT1906 at Electric Supplies on-line

277 Volt

T1906 and T1976 control 277VoltNo black tape added to white wireHow to wire 3 phase timer

For T1906 and T1975, White wire is HotFor T1905 and T1975, White wire is Neutral

208-277V Two LoadsT1906 and T1976 control two Loads

Each Load is same voltage ranging from 208Volt to 277VoltNeither Load is turned ON at same time. Either NO Load or NC Load is active, but not both same time.

Bare ground wires connect to green screw.When using White wire to carry Hot, then add black tape to tell next electrician that wire carries voltage.

To control different voltages, use timer with dry terminals such as GM40. How to wire GM40

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240VT1906 and T1976 control 2-speed pump

Low speed is connected to NC terminal, and then pump operates continuously in low speed until timer turns ON.When timer turns ON, High speed turns ON.Diagram applies for both 120V and 240V 2-speed pool pumps.Always check pump voltage and wiring diagram located on nameplateOther timers can be used for 2-speed pool pump:Intermatic GM40, GE 15207 series, T106 timer, Tork DTU40 timerPump operates continuously. Install another timer on White Hot-neutral line to turn pump ON-OFF

Bare copper ground wires connect to green ground screw

Change water heater temperature using Intermatic T1906 and T1976 timersAlso applies to Intermatic GM40 and WHQ timer and  Tork DTU40 timer and GE 15207 series and Intermatic T106 timer

240 Volt   T1906 and T1976

Use timer for two different temperatures on electric water heater.

Either upper thermostat and element have power or lower themostat and element have power. But not both at same time.

Install ECO-protected thermostat for lower thermostat.Both upper and lower parts of tank are ECO-protected from overheatingRewire tank so upper and lower parts are separate.Use GM40 timer to switch power between lower and upper parts of tank.

Normal operation, the lower thermost and element receive power and keep tank at temperature set point. Upper thermostat and element have no power.This is called 'redundant' water heater operation. This technique for heating tank more rapidly after cold water first enters tank. How to wire thermostats

When timer activates, power to lower part of tank turns OFF. Power to upper part of tank begins. Upper thermostat is set for higher temperature.Since tank is at regular temperature, the higher setting means upper element will turn ON and begin heating tank to higher set point.

Use this technique to heat water very hot for laundry cycle.Disadvantage: The lower part of tank will cool rapidly as new cold water enters tank, so this technique is good for making short-term batches of hot water.

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240 Volt

Toggle water heater between 240 Volt or 120 Volt

Move clock motor wire from Com to NO terminalUse for off-peak, use for 120Volt solar panels

How to wire water heater for 120VoltWires inside water heater do not change.Elements and thermostats will work with 120Volt or 240Volt

Element watt consumption drops when voltage dropsNo need to change breaker.Just run additional neutral wire to timer.Element rated for 4500 watts @ 240Volt, will consume 25% or 1125 watts @ 120Volt

240 Volt

Toggle water heater between peak and off-peak operationUse this wiring for Peak and Off-Peak

How it works:

When timer is ON, both upper and lower thermostats operate in normal non-simultaneous operation.

When timer is OFF, the lower part of tank receives no power. Upper part of tank receives power and keeps upper part of tank hot. Amount of available hot water is reduced.

How to wire thermostats

T1905 and T1975 with day skipperSame wiring diagrams above apply to T1905 and T1975, except 120Volts

T1905 and T1975 timers have WG730 120 Volt clockSame wiring applies to both T1905 timer and T1975 timerOnly difference between these two timers is the day skipper wheel on T1975

NO terminal is normally open. NO turns 'on' with timer settings. This terminal used for water heater circuit shown on left.NC terminal is normally closed. NC turns 'off' with timer settings.

Timer turns off Black hot wire, so 120V water heater has no electricity when timer is off.

Wires at 120V water heater: Connect black-to-black and white-to-white wires at water heater.

Read T1905 manualT1905 for 120 V at Grainger