warmup WSM-252W Underfloor Heating
The Warmup WSM-252W is a WiFi-enabled panel to operate your in-ground snow melting system. The panel contains load switching capabilities (up to 252 Amps/240V) and is triggered by the weather forecast.
Although it has a manual power button on the enclosure frame, the WSM-252W is intended to operate automatically and without the need for external sensors. The device will monitor the weather forecast several times per hour looking several hours in advance (typically 2 hours). Once the weather data matches trigger points set in the parameters, the system will engage.
This allows the system to pre-heat before the snowfall, making it significantly more prepared during heavy snowfalls. It will aim to get the outdoor slab to 50-55°F before the precipitation event and thereby prevent any accumulation of snow.
The system carries an internal manual timer as well as app-based time settings. Please refer to the below manual for complete instructions.
The WSM-252W is intended to operate Warmup’s WSM and WSMM snow melting cables and mats in in-ground snow melting applications.
NEMA 1 for indoor mounting
Two (2) 64A/4P relays with 120V
- Switching Voltage
MAX load bearing of 252A/240V at 2-phase power and up to 378A/277V at 3-phase power
UL-approved components assembled in UL 508 facility
The device must be mounted indoors and within reach of the dwelling’s WiFi signal.
The WSM-252W is currently designed to operate in-ground snow melting systems and is not yet calibrated to operate roof melting applications. While it can perform that function, it is not yet updated with the specific requirements of such applications (run-off melting, etc).
The WSM-252W is specifically designed to work with the wattage output of cables manufactured by Warmup Inc / Warmup PLC. Warmup makes no guarantees as to its suitability when used with non-Warmup systems.
The system requires two sets of inbound power: 120V supply to power the WiFi relay and coils on wiring terminals 1 & 3 and 240V supply power to the load side of the relays to activate the snow melting system (at 240V). Adjust inbound voltage based on the power requirement of the WSM/WSMM snow melting system.
While external snow sensors are not required for the WSM-252W to operate efficiently, they can be wired as a backup to terminals 5 and 6. The approved setup with ETO2 or ASE-DS type outdoor sensors should be supplied with 120V power to activate the devices and eventually trigger the coils (120V) to operate the system.
Do note that these sensors are redundant to the WiFi operation of the system and the setup is “either/or”. The device cannot automatically switch from WiFi to wired sensor-based activation. If you want to install the sensors as a backup but wish to operate with the WiFi feature, simply complete the wiring without actually fitting the terminations into poles 5 and 6 of the wiring terminals.
(See wiring diagram at the end of this manual)
Activating your system
You can activate your WSM-252W manually by pressing the on/off button on the door of the enclosure. This is accessible to the user from the outside of the panel.
However, at the initial set-up, the internal timer should be set up with the desired number of hours for the timer to function upon being triggered by the ON/OFF button.
The timer can be set from 1 to 99 hours and Warmup defaults the timer at 1 period of 10 hours. We do not recommend less than 5 hours for proper snow melting results. This can be changed at any point by the user.
When changing the settings of the timer, you must first disconnect power to the whole unit, then change settings, then turn power back on. This is not only for safety reasons but also because the timer requires a power-cycle reset when its settings are changed.
The manual operation of the system can serve as an override to the WiFi activation. This means that at any point, the user can activate the system manually without interrupting the regular operation of the system using the WiFi signal and the app’s parameters.
The breaker must be turned off before adjusting the timer settings.
- Turn the top orange dial to 10h
- Turn the middle orange dial to .4 (or however many hours you would like to set the system to).
- Example: .4 = 4 hrs, .5 = 5 hours
- The bottom dial should be set to D mode
To activate your WSM-252W automatically as it was designed to be, you must first download the Warmup WSM application available in your iOS or Android app store.
Upon download, verify that your system is properly wired and powered so that it can emit the necessary signals to your home’s WiFi router. This signal will then be picked up by your phone for the activation of the app.
With all that verified, open the app and follow the prompts. You will need to key in your WiFi’s “name” (SSID) and the password to connect to it.
Once the connection is established, the following step will be to connect your phone with the WSM-252W.
To do that, go to your phone’s SETTINGS where you can review the available WiFi signals.
A new signal will have appeared with the format “Shelley-IOT-XXXX-XXXX” where the “x” can be a series of numbers and letters. Assuming it is the only WiFi signal starting with Shelley-IOT… select it and let your phone connect to it.
NOTE: newer versions of the WSM-252W have a different relay and signal. If your WiFi relay is a round blue box, a different, unique WiFi signal will be emitted that may not look like “Shelley…” but like “shelly1” instead
This will pair up your phone with the device. You can repeat this operation with any other phone.
Once it has connected to the Shelley network, it will prompt you to return to the SETTINGS of your phone and return to your home’s WiFi network as it originally was. This is simply to return your phone to its original set-up. The temporary switch to the Shelley network allowed the WSM-252W to pair up with your phone specifically and it will now link directly with your home’s router.
Over the next few screens, you will be guided to set up your system and name it. It will select your location if your phone allows it in order to determine the exact location of your device and by extension your driveway and snow melting system. This is important as the weather forecast will be checked for that location specifically.
Default parameters have been preloaded for a typical snow melting system. You can click on the EDIT icon (pen and paper) of your snow melting system and change the following:
If you wish to change the name of your system you can do it here.
STARTING TRIGGER OR %PRECIPITATION The weather forecast indicates the chances for snow over the following several hours in your area. Your device will trigger once the probability is above the percentage identified in your settings. We recommend 70-75% probability, but a high % makes the system less sensitive and a lower percentage makes it more sensitive. This means that in areas with fast-changing climates, you may want a more sensitive system.
As a default, the system will turn on 2 hours prior to the forecasted precipitation event. If your location requires more time, you can change this here. You can simply let the default setting run for a few snowfalls and adjust later on. If your wattage output is lower than 50 watts/sqft (cables at 3” spacing) you may need more than 2 hours to get your slab to temperature prior to the snowfall. We recommend setting this to 3 or 4 hours for spacing of 4” (42w/sqft) or 5” (35w/sqft).
It is recommended to not allow the system to function when outdoor temperatures are below 0°F / -18°C. This is because the power required to heat the slab to 40°F is simply too great and it is possible that the system may not cope with the requirement. At least not efficiently. The default setting is to not allow this, but you can force it ‘on’ here.ABOVE 50°F
Similarly, we recommend letting the system automatically power down if the outside temperature reaches 50°F or more. This is because at these temperatures, natural snow melting occurs and you may prefer to let nature take its course rather than spending Kilowatts to melt the snow. Leave on “Yes” if you would like the system to turn off above 50°F.
ACTIVATION LENGTH (MAX. RUN TIME)
The system is pre-programmed to not operate for more than 24 hours. In the event it is struggling to keep up with the weather or some of your settings have called for it to operate continuously, this safeguard prevents the system to operate more than 24 hours at a time. It is not recommended to turn this off.
Terminal 6 Terminal with DS-2
- Step 1
Terminal with DS-2
- Step 4
Terminals with 4iE
- Step 1
Terminals with 4iE
www.warmup.com Technical Helpline