MTA NGSi 05, Technical Manual, Page: 25 / 58

TECHNICAL MANUAL
Chapter 9
- User - Control Interface
NGSi 05÷15
23
ENGLISH
EN
The data in this manual are not binding and they can be modified by the manufacturer without notice. Reproduction of this manual is strictly prohibited
backup heater to that is acts also as a backup heater on system side: for this purpose set r10=1 and r15=2 (for other settings of r15 refer to
Point 9.16); furthermore no digital output must be set as the system backup heater.
9 . 1 4 S y s t e m b a c k u p h e a t e r s
The system backup heater output is active only with the settings H58=22 (output 230V AEH AEHN already set by default) or H61=22
(output 230V NO1 N, not set by default) (for other outputs which can be used in the terminal board and the related settings refer to Point
9.25). The heater is enabled using parameter
r10=1 . It is also necessary to set the parameter r24 to 1 or to 3 (refer to the r24 parameter
settings explanation in Point 9.18). In heat pump normal operation mode, if the control temperature remains lower than the water setpoint
less r11 (°C) and the machine is in cut-out mode for the intervention of an alarm, the heater is enabled. It turns off when the machine comes
out of the cutout alarm. The backup heater can also be activated with the heat pump not in cut-off mode, depending on the machine operation
in the joint ranges or in replacement mode indicated in Point 9.18, if the production of hot water continues for a time longer than the
operation time set with the parameter
r12 (minutes), always if the control temperature remains below the water setpoint minus r11 (°C). In
these cases, the heater is switched off when the machine reaches the setpoint set (also taking into account any offset set with parameters r29
or r30 (refer to Point 9.18).
9 . 1 5 S y s t e m s b a c k u p h e a t e r i n d e f r o s t m o d e
During the defrost cycle (see Point 9.21), setting r21=1 (in addition to r10=1 and r24=1 or 3 ) the electric heater activates on the system side,
if required (control temperature below the water setpoint minus r11 (°C)), without waiting for the time defined by r12 .
9 . 1 6 D o m e s t i c h o t w a t e r b a c k u p h e a t e r
This is an additional resources for heating the water in the domestic hot water tank if the compressor alone is not able to reach the setpoint
within a reasonable time. The domestic hot water backup heater output is only active with the settings
H58=26 (output 230V, AEH, AEHN
not set by default) or H61=26 (output 230V NO1 N not set by default) (for other outputs that can be used in the terminal board and their
configurations refer to Point 9.25).
The heater is enabled with the parameter
r15=1 (with r15=0 the heater is disabled). It is also necessary to set the parameter r24 to 2 or to 3
(refer to the r24 parameter settings explanation in Point 9.18). If the production of domestic hot water continues for a time longer than r16
(minutes) or if the machine enters in cutout mode for the intervention of an alarm, the heater is activated. It turns off when the machine
finishes the production of domestic hot water (taking into account a possible offset of the setpoint set with the parameter
r31 , as explained in
Point 9.18).
9 . 1 7 B a c k u p h e a t e r s s e l e c t i o n m o d e
It is possible to set the backup heaters activation priority order on the system side and domestic hot water side, in particular the
configurations are:
1. r14=0 (default), the heaters can be activated simultaneously if present;
2. r14=1 , the heaters are activated in exclusion to each other:
• r20=0 , system priority (the domestic hot water heater is activated only if the temperature control is reached for the system
side heater);
• r20=1 , domestic hot water priority (the system side heater is activated only if the temperature control is reached for the
domestic hot water side heater).
9 . 1 8 A c t i v a t i o n o f b a c k u p a n d h o t w a t e r t a n k h e a t e r s i n j o i n t o p e r a t i o n
m o d e / c o m p r e s s o r r e p l a c e m e n t m o d e
The compressor use is inhibited in case of low outside temperature.
Considering this mode, there are 4 areas of operation of the machine:
1. operation in heat pump mode (normal operation, with the compressor enabled) in which the backup heaters and the hot water
tank intervene only in case the heat pump goes into alarm;
2. joint operation (First range) , in which the compressor use is enabled in synergy with the auxiliary heaters (in winter or
domestic hot water modes, if the outdoor temperature drops below r22 (°C) (default 7°C) but remains above r28 (default -7°C).
The operation returns normal if the temperature rises above r22 +1.0 (°C). In particular, in this range of operation, the auxiliary
heaters and the hot water tank are activated after a time defined by r12 (minutes) for the system side and by r16 (minutes) for
the domestic hot water side, from the activation of the heat pump, according to the priorities set by the parameters r14 , r20
(refer to Point 9.17) and r23 , r24 (see following explanation). If the backup heaters are used, they must be enabled also from the
parameter r10 (system backup heater case, see Point 9.14) and from the parameter r15 (domestic hot water backup heater case,
see Point 9.16).
3. joint operation (Second range) , in which the compressor use is enabled in synergy with the auxiliary heaters (in winter or
domestic hot water modes, if the outdoor temperature drops below r28 (°C) (default -7°C) but remains above r08 °C (default -
16°C). The operation returns normal if the temperature rises above r28 +1.0 (°C). In particular, in this range of operation, the hot
water tank is activated first, then the heat pump and the auxiliary heaters after a time defined by r12 (minutes) for the system
side and by r16 (minutes) for the domestic hot water side, according to the operating priorities set by the parameters r14 , r20
(refer to Point 9.17) and r23 , r24 . If the backup heaters are used, they must be enabled also from the parameter r10 (system
backup heater case, see Point 9.14) and from the parameter r15 (domestic hot water backup heater case, see Point 9.16).
If the system or domestic hot water backup heater must start after the heat pump, it is necessary to enable the hot water tank
setting
r23 with one of the values among 4 , 5 or 6 , instead if the system heater has to start before the heat pump r23 must be
configured with 0 , 1 , 2 or 3 (therefore even when the hot water tank is not used).
4. operation in replacement mode , in which the compressor use is inhibited and the auxiliary units operate in their replacement
according to the times defined with r12 (minutes) for the system side and r16 (minutes) for the domestic hot water side, (in winter or
domestic hot water mode, if the outdoor temperature drops below r08 (°C), default -16°C). The compressor is enabled again if the
temperature rises above r08+ r09 (°C) (r09=1.0°C by default).