ETO2 Controller for Ice & Snow Melting

When snow is detected, snow melting is started in delta configuration. In ‘after run’ time the controller switches to star configuration (1/3 power). In delta configuration output 1 + 2 is active – in star configuration 1 + 3 is active.

Question
What do I do with the last two wires (pink and grey)?

Reply
The ETOR-55 is now fitted with the same cable as the ETOG-55 – and can therefor be connected in the same way as the ETOG. Alternatively these two wires can be cut off (wires are not connected/used in sensor).

Question

The temperature sensor in my embedded ETOG sensor doesn’t work. What do I do if I don’t want to dig up the sensor?

Reply

• Remove the wires for the temperature sensor from the ETO2 terminals 13 & 14 or 17 & 18
• Mount a ETF-744/99 sensor on the outdoor sensor input terminals 31 & 32
• Reinstall the unit (Password 1202)
• Set the used sensor input to ETOR instead of ETOG
• Set outdoor sensor to ETF

Question

When reading outside air temp my ETOG sensor can be several °C/F higher than the current outdoor/ground temp.

Reply

The shown temperature is the sensor temperature. Since the sensor – during moist detection – is heated, the measured temperature doesn’t always match the outdoor/ground temperature.

Question

I need to calibrate my ETO2+ETOG embedded sensor, as the sensor temperature differs from that showed on the ETO2 display.

Reply

1. Disconnect sensor from terminal 11 and 12 (sensor heat) on ETO2
2. Wait a few hours until the sensor has the same temperature as the ground
3. Measure real ground/sensor temperature and compare with the temperature shown in the display of the ETO2
4. Program offset for the relevant sensor to match the difference between the two temperatures (measured / real)
5. Connect sensor to terminal 11 and 12 on ETO2

Question

There is no yes/no indication on the moisture indicator

Reply

If the outdoor temperature is above setpoin,t the ETO2 won’t look for snow and therefore the moist sensing indication is blank.

Question

How do I turn Output 3 on on the ETO2 controller?

Reply

Output 3 is activated when there is a heat demand (snow melting) in 1-zone configuration. In this configuration all 3 outputs are activated at the same time.

Question

If the there has been a power outage at the residence, and power remains out for a significant period of time (for example, 4 to 6 hours) does this effect the programing to the ET02 controller? Even if power is out, does the unit keep the programmed settings?

Reply

The settings are stored in a EEPROM which means that the settings will continue to be stored.

Question

What is the voltage output of the three output relays? The manual shows .3 x 16amps

Reply

The three output relays and the alarm relay are all voltage-free (potentinal free/dry contacts) outputs.

Question

If I use an ETO2 controller with an ETOG sensor in a water-based 1 zone heating system do I also need to supply/return water temperature sensors?

Reply

Yes – if you configure the controller to water based you have to connect a supply and return water sensor. If you don’t want to supply and return water temperature – change the configuration to Electrical 1-zone.

Question

When you set a desired temp for let us say “Set Temp 1”, -how does the ETO2 function when ETOG connected running in electric mode

Reply

If moist is detected, and the temperature has reached a level below the “Set Temp” the relays 1, 2 and 3 are closed for the 1 zone application. – For the 2 zone application, both the moist and low temperature is needs to trigger either zone. If the temperature rises above the “Set Temp” or moist is no longer detected, the ETO2 enters the afterrun mode (these are independent for each zone in the 2 zone application).
Note: Relay 3 is not used in the 2-zone application.

Sensors used to measure water temperatures cannot be used with “Electric” applications.

Question

When you set a desired temp for let us say “Set Temp 1”, -how does the ETO2 function when ETOG connected running in Water Based Mode with Supply and return sensors on the pipes.

Reply

If moist is detected, and the temperature has reached a level below the “Set Temp” the relays 1 and 2 are closed, after a minute relay 3 closes as well. If the temperature rises above the “Set Temp” or moist is no longer detected, the ETO2 enters the afterrun mode.

If moist or a temperature below the “Set Temp” is not detected, the ETO2 is operating in an “Idle” state, every 15 minute the 2’nd relay is closed for one minute, if then the return water is below the “MIN WATER” temperature, the 1’st relay is closed after a minute and the 3’rd relay is closed after another minute. If the return water is above the “MIN WATER” temperature the 2’nd relay will close again after a minute.

The 0-10V output can control some condensing boilers directly.

Question

When you set a desired temp for let us say “Set Temp 1”, -how does the ETO2 function when ONLY a slab sensor running in electric mode.

Reply

Same as a. but moist is not taken into consideration.

Question

When you set a desired temp for let us say “Set Temp 1”, -how does the ETO2 function when ONLY a slab sensor running in Water Based Mode with supply and return sensors on pipes.

Reply

Same as b. but moist is not taken into consideration.

Question

When you set a desired temp for let us say “Set Temp 1”, -how does the ETO2 function when To each one of the previous scenarios, how does the outdoor ETF sensor change the functionality?

Reply

The ETF sensor does not change the functionality, it gives the system a opportunity to start earlier if the ambient temperature drops fast. The first sensor that register a temperature below the “Set Temp”, activates the system

Question

I have an application currently where they have a hot water source (constant 125 F water to the system when the pump is on) and want to keep the concrete at 45 F all the time. They did not install an ETOG, only a slab sensor. In this case, how should the ETO2 be setup to maintain 45 F using the slab sensor?

Reply

Use the “HYDRONIC” application

Use the 2’nd relay (terminal 5 and 6) for the pump.

Connect the slap sensor (the sensor has to be a NTC 12K Ω @ 25° C) to the terminals 13 and 14

Short circuit the terminals for the moist sensor 15 and 16.

Use a ETF-522 to measure the return water temperature connected to the terminals 29 and 30.

Use a 10K Ω resistance between the terminals 27 and 28 (This will simulate a temperature of approximately 84 ° F at the WATER SUPPLY – The “MAX WATER” has to be set a bit higher than 84° F).

The “MIN WATER” must be set to 45° F