Heat-Trace in Hot Water Maintenance
Heat-trace is used in many aspects of everyday modern life that mostly goes unnoticed. One main example of this is the ability to access hot water quickly from any faucet in a large building no matter how far from the water heater it is. This is a function of a...
Power Line Noise Issues with Ground Fault Protection Equipment
Due to the high sensitivity of ground-fault-current detection circuits, it is possible that excessive line noise on the power source wiring can cause an alarm. This can occur in the form of a ground-fault alarm, a stuck-relay alarm, or a ground-fault circuit alarm....
New line of Heat-Trace controls
This past July Environmental Technology released its new line of microprocessor-based heat-trace controls, replacing its already successful SST line which has been a trusted industry standard since 2011. The new GPT and FPT heat-trace controls were created with input...
How do I set up my GPT for a RTD sensor?
The GPT unit comes with a thermistor (two thermistors with the GPT 230) but is also compatible a 2-, 3-, or 4-wire RTD sensor. The diagram illustrates the correct wiring and DIP switch configuration for each temperature sensor wiring scheme. It is important that you...
Difference between 277 single phase and 277/480 3 phase unit?
The difference is the step down transformer that provides the power for the internal circuitry. On the 277 single phase the transformer is 277 VAC to 24 VAC and you will note that its primary winding is connected to the top and middle poles on the contactor. On the...
Can the APS activate on temperature only?
The APS-C series systems are designed to turn on and off, as the weather requires heat to deal with snow or icing conditions. Although a thermostatic dry contact switch can be used to override the system on for temperature only, is not recommended since it will reduce...
External contactors used with the APS-4C?
No, using external contactors will cause the GFEP circuit on the APS-4C to detect the inductive load of the contactors coil as ground fault and alarm the system every time the contactor is turned on. In order to increase the size of the application, a...
Flashing supply light.
A flashing supply light indicates a missing or broken High-Temperature Limit sensor. This sensor is required to make the APS-C series controller to work. It is required on all of the APS-C series controllers. The sensor is not polarized and must be connected to pins...
Delay between SC-40C and APS-4C?
Why is there a delay between when the APS-4C turns on and when the SC-40C comes on? This delay between the APS-4C and the SC-40C is programmed into the system in order to reduce surge current. When the heaters are turned on they will have a large inrush of current for...
Snow light on SC-40C stays on longer than APS-4C
The snow light stays on longer for the SC-40C than the APS-4C because the APS-4C gets its command from an actual snow sensor where the SC-40C’s get their command from the APS-4C. When the snow sensor’s moisture grid dries out, it no longer sends a snow present command...
Is a snow sensor required for a SC-40C?
No, the SC-40C does not use a snow sensor, it is completely controlled by the attached APS-4C. However, the SC-40C does require the High-Temperature sensor Thermistor to be connected (or bypassed with a 470K-ohm resistor) in order for the unit to operate. The SC-40C...
Temperature sensor was not installed
The high limit temperature sensor is intended for two purposes, either as a slab sensor when the APS-C series unit is used for heating sidewalks, patios or drives or for ambient air temperature when the unit is used for roof and gutter melt systems.In roof and gutter...
Can I simulate a sensor call for heat?
Yes, you can simulate a sensor call for heat to test the system by putting a jumper between pins 1 and 2 of the class two terminal blocks, the system will respond as if the sensor were seeing snow conditions. The snow and heat indicators will come on and relay or...
Snow sensor not detecting snow outside?
There can be several reasons for this. First, start by checking the snow sensor supply voltage between pins 2 and 3 of the class two terminal blocks. It should be close to 24 VDC (the label on some unit incorrectly say 24VAC). If there is no voltage then check the...
Why do I have a red GFEP light on?
The GFEP indicator will come on when a ground fault occurs in one of the heater circuits. The insulating resistance of the heater cable is breaking down or the cable has been damaged allowing current to pass to ground thru an incorrect pathway. Left un-repaired the...