Toshiba Estia RUA-CP1701H, Service Manual

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Monobloc Outdoor Unit Service Manual
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Fixed Speed Pump Option (pmp_type = 1)
The fixed speed pump option is fitted in the factory. ON / OFF control of the pump is available from the NHC board
via an internal contactor as shown below:
The speed of the pump can be adjusted using a manual speed selector switch located on the pump electrical box.
There are 3 pump speeds available on the fixed speed pump.
The following table shows the minimum and maximum pressures required in the hydronic circuit for correct operation
of a unit with the fixed speed pump option fitted:
Hydraulic circuit
Minimum pressure at the
suction of the pump to avoid
the cavitation phenomena.
Maximum pressure at the
suction of the pump before
the opening of the water relief
valve *
Fixed speed hydronic
module
50kPa (0.5 bar) 300 kPa (3 bar)
To ensure the correct and safe operation of the system a minimum water flow rate must be maintained throughout the
hydronic circuit. If the minimum flow rate is not maintained then the contacts on the flow switch, incorporated into the
fixed speed pump hydronic module, will OPEN and the system will STOP due to a low water flow (alarm code 32 – the
system will STOP after 5 attempts to run).
The minimum flow rates for the ESTIA Monobloc outdoor units, fitted with the fixed speed hydronic module, are
shown below:
RUA-CP170 / 2101H units with fixed speed hydronic module
Minimum water flow rate, l/s Maximum water flow rate, l/s
17
0.45 1.4
21
0.57 1.6
Fixed speed pump characteristic (static pressure v water flow rate):