20
HPF-PS Series Instruction Manual —
P/N LS10227-003HP-E:C 2/2/2022
Installation
Ground Fault Detection
2.8.2 Daisy-chaining Multiple Units
The number of power supplies which can be daisy-chained is limited by the line resistance and current draw limitations of the upstream mod-
ule or NAC output circuit. Refer to the module, power supply, or fire alarm control panel manual to confirm these circuit specifications.
Maintain separation of power-limited and non-power-limited wiring as shown in Figure 2.6.
Figure 2.13 shows the controlling signal connected to Input 1 of HPF-PS1. However, typically any available Input of HPF-PS1 can be used.
The following notes apply to Figure 2.13.
1.
The HPF-PS units can be set to work in either Default or Retrofit modes. In standby condition, the input EOL relays are open when they
are used to report troubles, depending on the configured operating mode. Refer to Table 5.1 on page 34. In alarm condition, all inputs
will close their EOL relays to allow the daisy-chaining of input signals.
2.
The debounce/dejitter setting must be set to a value that allows the correct detection of input signals. See Table 3.3 on page 24.
3.
In Default mode, ground fault supervision is provided via the general trouble relay. For ground fault supervision in Retrofit mode, refer
to Table 5.1. Refer to Section 2.9 for different methods of ground fault monitoring of the power supply. The NAC circuit or remote sync
output is to be monitored by the host FACP.
2.9 Ground Fault Detection
When connected to an FACP, the host FACP must monitor for all ground fault conditions.
There are three ways to monitor for ground faults in the power supply when cascading (up to four) or daisy-chaining power supplies.
1.
The negative (-) battery terminal of the HPF-PS power supply must be connected to the negative (-) battery terminal of the host FACP.
Battery wiring is non-power-limited. Power-limited and non-power-limited wiring must be wired with a minimum of 0.25” spacing in
between and enter/exit through different knockouts. When cascading multiple power supply units, continue connecting the negative
FACP
NAC or remote
sync output
Figure 2.13 System Sync Connections Triggered by FACP - Daisy-chaining
HPF-PS1
HPF-PS2
HPF-PS3
to next power supplies
in daisy-chain or EOL
(if Class B) or host fire
panel (if Class A).
