CLCH-SVX03C-EN
67
Wiring
All direct-digital controllers (DDCs) are provided with line voltage to 24 Vac control transformers
mounted and wired in the starter or variable-frequency drive (VFD) power box transformer plate
(see
Figure 62
) or 120 to 24 Vac control transformers mounted and wired in the auxiliary control
panel (see
Figure 64
).
Figure 63
shows a typical VFD power box.
Note:
The valve jack/junction box is typically located at the air-leaving side of the coil connection
inside panel. For coils with headers on both sides of the module, the valve jack is located
at the return connection for water coils and the supply connection for steam coils.
Figure 62. Transformer plate
Figure 63. Variable-frequency drive (VFD)
Figure 64. Controller with power box attached
