Electrical Supply; External Controls - Lochinvar HERALD HCB46CE Installation Manual

15.0 ELECTRICAL SUPPLY

Wiring external to the equipment must be installed in accordance with the I.E.E. Regulations and any local
regulations that apply.
Model
HCB46CE
HCB61CE
HCB86CE
15.1.1 ELECTRICAL SUPPLY REQUIREMENTS
WARNING: this appliance must be earthed
A suitably competent person must check wiring. Normal supply required is 230 volts ac,
single phase, 50 hz. An isolator with a contact separation of at least 3mm in all poles should
be sited close to the equipment and must only serve that equipment. The double pole
switch must be readily accessible under all conditions
15.2

EXTERNAL CONTROLS

The Herald boiler can be controlled via a BMS system either utilising a simple on/off arrangement or by directly
modulating the output. The boiler has the following inputs/outputs:
 Building Management System (BMS) 0-10VDC analogue input
 Volt-free "burner on" (runtime) signal
Volt-free "lock-out" (alarm) signal

0-10V "burner firing rate"

0-10V "Boiler pump speed"

 0-10V "System pump speed"
 24VAC auxiliary device enable signal (e.g. to start fan dilution system)
The Herald boiler is also compatible with the following control and safety systems allowing the boiler to operate as a
complete standalone system. See the relevant sections within 17.4 for details of programming the various functions
required for a standalone system.
 Room thermostat up to 3no (on/off type)
 System sensor (modulating type)
Storage vessel thermostat (on/off type)

Storage vessel sensor (modulating type)

Internal sequencing control

 Gas pressure switch (e.g. gas booster under pressure/over pressure safety switch)
 Water flow proving device (e.g. differential pressure switch or flow switch)
Auxiliary safety system proving switch (e.g. fan dilution system proving switch)

15.2.1 REMOTE ENABLING
There are two ways to enable the Herald boiler using a BMS:
1. Using a 0-10V signal via connections 35-36
2. Using a volt free enable signal via connections 21-22
The boiler will still fire on a DHW demand if the Herald is directly controlling the DHW via the
sensor point at 29-30
Normal Supply Voltage
230V AC
50 Hz
1 PH
External Fuse Rating
6.0 A
Power Consumption
120 W
144 W
180 W
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