19
31. 08. 21. Document Number 671746
Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA | nuaire.co.uk
BPS (V/T)-ES
Installation Manual
8.0 FROST COIL INSTALLATION (OPTIONAL
ANCILLARY)
8.1 LPHW Frost Coil
LPHW frost coils are fitted with a frost stat on the air in side. Units are
NOT provided with valve and actuator. If the frosts stat switches to
a frost condition, to signal will be sent to open the valve actuator (by
others). The valve will open whether the fans are running or not. This is
for pipe freeze protection. The LPHW section requires its own supply in
order to power the valve actuator.
8.2 Wiring - LPHW Frost Coil Unit Sizes 07 - 42
External
Rotary
Isolator
N
L1
LPHW Frost Heater Supply
(Overcurrent protection by others)
Recommended Frost
Temperature Setting 4°C
Heater Temperature
Setting
°C
-8
-2
2
8
36
Wiring - LPHW Frost Coil 07 - 42
8.3 Electric Heater Frost Coil
Electric heater frost coils are fitted with its own internal control panel.
The control is powered by a 400Vac 50Hz 3 phase & Neutral supply.
This must be isolated local to the unit and fitted with appropriate
overcurrent and fault protection. It connects to the main unit via
“plug and play” interconnecting looms (see Section 6.4). No external
connections are required. Electric heater elements are protected by
a fail-safe over-temperature switch which will disconnect the heater
supply if a temperature of 80°C is reached. Once the elements cool, the
switch will reset but a power cycle is required to reset the heater supply
contactor.
The frost coil is fitted with a burst fired controller with integral set
point, air off thermistor, air in frost stat, thermal cut-out and contactor.
The burst fired controller is only enabled if the frost stat reads a frost
condition, the over-temperature cut-out is healthy AND a 24vac fan
run signal is received from the main control panel. Once enabled the
burst fired controller will increase heating output to achieve the set
point set by the physical dial on the unit.
8.4 Wiring - Electric Heater Frost Coil Unit Sizes 07 - 22
External
Rotary
Isolator
N
L1
Electric Heater
Power Supply
L2
L3
Recommended Frost
Temperature Setting 4°C
Heater Temperature
Setting
°C
-8
-2
2
8
37
Wiring - Electric Frost Coil 07 - 22
8.5 Wiring - Electric Heater Frost Coil Unit Sizes 32 - 42
External
Rotary
Isolator
N
L1
Electric Heater
Power Supply 1
L2
L3
External
Rotary
Isolator
N
L1
Electric Heater
Power Supply 2
L2
L3
Recommended Frost
Temperature Setting 4°C
Heater Temperature
Setting
°C
-8
-2
2
8
38
Wiring - Electric Frost Coil 32 - 42
8.6 Electrical Supply FLC’s
‡ Double electric heater models require separate supplies for two
heater sections, each with an appropriate overcurrent current
protection device.
Unit Size
Electric Frost Heater
FLC (Anciliary)
LPHW Frost Coil FLC
(Anciliary)
B*07V/**ES
17.5 A
0.1 A
B*07T/**ES
17.5 A
0.1 A
B*12V/**ES
35 A
0.1 A
B*12T/**ES
35 A
0.1 A
B*17V/**ES
52.5 A
0.1 A
B*17T/**ES
52.5 A
0.1 A
B*22V/**ES
52.5 A
0.1 A
B*22T/**ES
52.5 A
0.1 A
B*32V/**ES
52.5 A + 35 A ‡
0.1 A
B*32T/**ES
52.5 A + 35 A ‡
0.1 A
B*42V/**ES
52.5 A + 52.5 A ‡
0.1 A
B*42T/**ES
52.5 A + 52.5 A ‡
0.1 A
