72
g. Hydronic assembly shall have factory
supplied electric freeze protection to –20 F
(–29 C) when optional heaters are used.
h. Piping shall be type-L seamless copper
tubing.
5. With VFD (these comments are applicable in
addition to the comments in section L.4 when
the VFD hydronic package is employed
(30RAP070-090 only):
a. The drive shall be of the VVC-PWM (voltage
vector control - pulse with modulation) type,
providing near unity displacement power
factor without the need for external power
factor correction capacitors at all loads and
speeds.
b. The drive and motor protection shall
include; motor phase to ground fault, loss of
supply phase, over voltage, under voltage,
motor over temperature, inverter overload,
and over current. Over current is not
allowed, ensuring hydronic units will not
overload the motor at any point in the oper-
ating range of the unit.
c. Sensorless control software shall be available
in the hydronic unit to provide automatic
speed control without the need for pump
mounted (internal/external) or remotely
mounted differential pressure system feed-
back sensors. Control mode setting and
minimum/maximum head setpoints shall be
set at the factory and be user adjustable via
the programming interface.
d. The integrated control shall incorporate an
integrated graphical user interface that shall
provide running and diagnostic information
and identify faults and status in clear English
language. Faults shall be logged and/or
recorded for review at a later date. It shall be
possible to upload parameters from one
drive into the non-volatile memory of a com-
puter and download the parameters into
other drives requiring the same settings. The
keypad shall incorporate Hand-Off-Auto
pushbuttons to enable switching between
BMS and manual control. The drive shall
incorporate a USB port for direct connec-
tion to a PC and an RS485 connection with
Modbus RTU protocol. Optional protocols
available should include BACnet and
Lonworks.
e. The control shall have the following addi-
tional features: Sensorless override for BMS,
manual pump control or closed loop PID
control; programmable skip frequencies and
adjustable switching frequency for noise/
vibration control; auto alarm reset; motor
pre-heat function; six programmable digital
inputs; two analog inputs; one programma-
ble analog/digital output; two volt-free
contacts.
f. The hydronic unit shall be capable of operat-
ing in any of the following control modes:
1) Duty pump and standby pumps with
sensorless control.
2) Duty pump and standby pumps with
remote sensor or building system (BAS)
control.
M. Special Features:
Certain standard features are not applicable
when the features designated by * are specified. For
assistance in amending the specifications, contact
your Carrier representative.
* 1. Low-Ambient Operation:
Unit shall be capable of operating down to
–20 F (–29 C) with the addition of the field or
factory-installed solid-state Motormaster
®
V
control with condenser coil temperature sensor.
In addition, adequate field-supplied antifreeze
with suitable corrosion inhibitor protection shall
be field-installed in the evaporator circuit.
Additional components shall be required and
used in conjunction with the low ambient
device. Components include field-installed wind
baffles. If significant low-load operation is antic-
ipated, then hot gas bypass is recommended.
Motormaster
®
V control is standard on sizes
010 and 015.
NOTE: The motors associated with Motormas-
ter
®
V fan will be open type and shall have
class B insulation.
2. Unit-Mounted Non-Fused Disconnect:
Unit shall be supplied with factory-installed,
non-fused electrical disconnect for main power
supply. This is not available with dual-point
power on sizes 070-090.
3. Optional E-Coated MCHX Condenser Coil:
E-coated aluminum microchannel coils shall
have a flexible epoxy polymer coating uni-
formly applied to all coil external surface areas
without material bridging between fins or lou-
vers. Coating process shall ensure complete
coil encapsulation, including all exposed fin
edges. E-coat thickness of 0.8 to 1.2 mil with
top coat having a uniform dry film thickness
from 1.0 to 2.0 mil on all external coil surface
areas, including fin edges, shall be provided. E-
coated coils shall have superior hardness char-
acteristics of 2H per ASTM D3363-00 and
cross-hatch adhesion of 4B-5B per ASTM
D3359-02. E-coated products shall have supe-
rior impact resistance with no cracking, chip-
ping or peeling per NSF/ANSI 51-2002
Method 10.2 (U.S.A. Standards).
4. Remote Enhanced Display:
Unit shall be supplied with indoor-mounted,
remote, 40-character per line, 16-line display
panel for field installation.
Guide specifications (cont)
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