10
MSEV Series and USHX Hardware Installation Manual Rev 1.7
3
Electrical Wiring
After the mechanical installation of the MSEV series valve(s) and/or USHX(s) into the system, complete
the electrical wiring of the system by completing the following steps. Refer directly Section 3.2 to if more
than one unit was installed.
3.1
Single USHC and MSEV Series Valve or Single USHS
Do NOT turn the power source ON until all electrical wiring setup is complete.
1.
Check the voltage type (either 12V or 24V) of the MSEV series valve. It can be found on the MSEV
series valve model number label. The power source required will be based on the MSEV series
valve voltage type.
Ensure that the power source voltage matches the MSEV series voltage type. If a 12V
MSEV series valve is powered by a 24V power source, the valve will fail due to an
over-voltage. If a 24V MSEV series valve is powered by a 12V power source, the valve
will not fully open due to an under-voltage.
2.
Obtain a Class 2 24 VAC transformer with a capacity of 40 to 100 VA and an output of 24 VAC at a
frequency of 60 Hz. Alternatively, a 120 VAC to 12 VDC or 120 VAC to 24 VDC Class 2 step-down
power supply with a 40 to 100 W power rating may be used. The schematics of the power sources
are shown below in Figure 3-1.
For the user’s own safety, only Class 2 power sources should be used to power the
MSEV series valve and USHX devices.
Figure 3-1 Class 2 DC and AC power sources
3.
Double check the power source output voltage (AC transformer secondary or DC power supply
output).
