2. Control Functions
Control functions on the module
SMGB0082 rev.1 - 07/2015
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2.1.15 Attachment of snowfall switch (Forced fan operation)
In regions with snowfall, when installing a snowfall switch in the context of countermeasures to prevent the accumulation
of the snow while the chiller unit is stopped, the snowfall switch has to be wired to terminals [26] and [24] of terminal board
TB3 of the control circuit of the electrical box.
When the switch is ON, only the fan operates (at 30 Hz), even if the chiller unit is stopped or in thermo OFF.
However, the fan does not operate in the following cases.
1 In local settings
2 In case that the switch was set to ON before turning the power source on (including power failure)
3 In case of having stopped manual operation of the fan with the stop button on the main unit of the chiller unit.
Wiring of snowfall switch (please arrange wiring to each module)
26
24
Terminal board
Chiller unit side
Local works section
Snowfall switch
(Supplied locally)
N O T E
• It is possible to install and use automatic snow relays into this switch part.
• The use of this switch is only enabled during remote operation. It is necessary to pay attention when inspecting the
chiller unit.
• Once the fan is being started by the snowfall switch, operation continues for at least 10 minutes. Please take into
account that it is not possible to stop the fan with the snowfall switch during this period. (In case of emergency, please
stop with the stop switch of the chiller unit. )
• This switch is to be supplied locally.
• When using the function to control the number of units, please arrange the wiring to unit 1 (master unit).The setting
becomes enabled in all the units when the signal is input to unit 1.
