User Guide

65
Design Guide - HZH/HZV Series
HZ Series 60Hz
Engineering Specications – Page 6
Remote Service Sentinel:
Solid state control system shall communicate with thermostat to display (at the thermostat) the unit status, fault status,
and specic fault condition, as well as retrieve previously stored fault that caused unit shutdown. The Remote Service
Sentinel allows building maintenance personnel or service personnel to diagnose unit from the wall thermostat. The
control board shall provide a signal to the thermostat fault light, indicating a lockout. Upon cycling the G (fan) input
3 times within a 60 second time period, the fault light shall display the specic code as indicated by a sequence of
ashes. A detailed ashing code shall be provided at the thermostat LED to display unit status and specic fault status
such as over/under voltage fault, high pressure fault, low pressure fault, low water temperature fault, condensate
overow fault, etc. Units that do not provide this remote service sentinel shall not be acceptable.
Option: Lonworks interface system
Units shall have all the features listed above and the control board will be supplied with a LONWORKS interface
board, which is LONMark certied. This will permit all units to be daisy chained via a 2-wire twisted pair shielded
cable. The following points must be available at a central or remote computer location:
a. space temperature
b. leaving water temperature
c. discharge air temperature
d. command of space temperature setpoint
e. cooling status
f. heating status
g. low temperature sensor alarm
h. low pressure sensor alarm
i. high pressure switch alarm
j. condensate sensor alarm
k. hi/low voltage alarm
l. fan “ON/AUTO” position of space thermostat as specied above
m. unoccupied/occupied command
n. cooling command
o. heating command
p. fan “ON/AUTO” command
q. fault reset command
r. itemized fault code revealing reason for specic shutdown fault (any one of 7)
Option: MPC (Multiple Protocol Control) interface system
Units shall have all the features listed above and the control board will be supplied with a Multiple Protocol interface
board. Available protocols are BACnet MS/TP, Modbus, or Johnson Controls N2. The choice of protocol shall be
eld selectable/changeable via the use of a simple selector switch. Protocol selection shall not require any additional
programming or special external hardware or software tools. This will permit all units to be daisy chain connected by a
2-wire twisted pair shielded cable. The following points must be available at a central or remote computer location:
a. space temperature
b. leaving water temperature
c. discharge air temperature
d. command of space temperature setpoint
e. cooling status
f. heating status
g. low temperature sensor alarm
h. low pressure sensor alarm
i. high pressure switch alarm
j. condensate overow alarm
k. hi/low voltage alarm