7 | © Frio 2021 - Rev. 0.3 - Updated 3/2/2021
system from turning on and off rapidly if the temperature hovers near the setpoint. The user may set either the RTD
or Thermistor as the active temperature sensor to be used for control. Both the temperature setpoint and the dead-
band of the system can be set by the user. The dead-band is added to the temperature setpoint such that the system
will turn on when the temperature falls below the setpoint and will turn off again once the temperature rises above
the setpoint plus the dead-band. The active temperature sensor must be placed in a location where it can accurately
read the temperature of the system.
3.2.3
Manual Control
Manual control is available in two options, Always On, or Always Off. In always on mode, the device will remain on
indefinitely. In always off mode, the device will not turn on unless the user activates the manual override feature. To
manually activate the device using the Force On feature, select
Force On
from the
Main Menu
, then choose the time
that you would like the device to be on. The device may be forced on for 5 minutes, 1 hour, or 24 hours. To cancel
the Force On command, select
Cancel Force On
from the Main
Menu
. The Force On feature may also be used with
any of the other control modes selected. Users may also force the device on or off via the Frio Cloud platform as
described below. Future firmware versions will allow for manual remote activation via a local network over RS485.
3.2.4
Cloud Control
Frio S1 devices that are connected to the internet can take advantage of the Frio cloud platform, including cloud-
based control. The cloud platform allows users to view device information remotely including connection status,
heater status, and alarm information. Users can also view and adjust select device settings from the cloud platform.
Alarms can be viewed via the cloud platform but must be cleared via the HMI on the physical device.
Users can control devices from the cloud platform by setting an override which will hold the device ON or OFF for a
user-specified period. Overrides can be set for a maximum of 21 days. If a device loses power during the override
period, then subsequently regains power, the override will continue until the end of the set override period. An
override that was set from the HMI will reset on power loss. An override set from the cloud will survive power loss
once the device reconnects and will continue as an override until the end time set by the user is reached.
Snow-melting systems may be controlled automatically via the cloud platform using weather data. For more
information on cloud-based snow-melting control please see the Frio Cloud platform. Additional cloud-based control
modes will be available on future firmware versions.
3.3
G
ROUND
F
AULT
E
QUIPMENT
P
ROTECTION
(GFEP)
The Frio S1 device includes integrated Ground Fault Equipment Protection (GFEP) and had been tested to the UL 1053
end product standard. Ground Fault Equipment Protection is designed to shut off power to the heater in the event of
leakage current in excess of the GFEP threshold.
3.3.1
GFEP Overview
The GFEP circuit measures the sum of the current on the two conductors feeding the heater and compares this value
to a set trip level. If the value exceeds the set trip level, the controller will open the relay, shutting off the heating
circuit. Since the current flowing out to the heater should equal current flowing back from the heater, measured
ground fault current should be near 0 mA. If the value is greater than 0 mA, that is an indication that leakage current
is flowing to some other part of the system. Some leakage current can be expected with heat trace; however, systems
with high leakage current are dangerous and should not be used. The default setting for the GFEP Trip Level is 30 mA.