Specifications, Specification Value, 10.2 | SPX Cooling Technologies 1000

Marley / Sigma 1000/1200 CoolingTower / Specifications: Options

	Specifications	Specification Value
	Basin Heater:
10.2	Add the following paragraph in the	■The basin heater components described at left represent our rec-
	Cold Water Basin section: Provide	ommendation for a reliable automatic system for the prevention
	a system of electric immersion heat-	of basin freezing. They are shipped separately for installation at
	ers and controls for each cell of the	the jobsite.
	tower to prevent freezing of water in	If aggressive operating conditions are anticipated, change “galva-
	the collection basin during periods of
	shutdown. The system shall consist	nized” in paragraph 10.2 to “Series 300 SS”.
	of one or more stainless steel elec-	The ambient air temperature that you fill in should be the lowest
	tric immersion heaters installed in a
	galvanized steel heat shield provided	1% level of winter temperature prevalent at site.
	in the floor of the basin. A NEMA	Ask for Marley drawing 92-3627.
	4 enclosure shall house a magnetic	Ask for Marley drawing 92-3627.
	contactor to energize heaters; a trans-
	former to provide 24 volt control circuit
	power; and a solid state circuit board
	for temperature and low water cutoff.
	A control probe shall be located in the
	basin to monitor water level and tem-
	perature. The system shall be capable
	of maintaining 40°F water temperature
	at an ambient air temperature of __ °F.
	Wiring of the heaters and controls shall
	be the responsibility of the purchaser.
	Fan Motor Variable Speed Drive:
	Marley All Weather ACH550 System	■ Marley VFD drive systems are designed to combine absolute
6.4		temperature control with ideal energy management. The cool-
6.4	Add the following paragraph in the	ing tower user selects a cold water temperature and the drive
	Mechanical Equipment section when	system will vary the fan speed to maintain that temperature.
	VFD is used with customers Building	Precise temperature control is accomplished with far less stress
	Management System: A complete	to the mechanical equipment components. The improved energy
	UL listed Variable Speed Drive system	management provides fast payback. Indeed, many utilities offer
	in a NEMA 1 indoor, NEMA 12 indoor	generous rebates for users having installed VFD drives.
	or NEMA 3R outdoor enclosure shall
	be provided. The VFD shall use PWM
	technology with IGBT switching and
	integrated bypass design. VFD out put
	switching shall not cause mechanical
	issues with gearbox teeth or drive shafts.
	The VFD shall catch a fan spinning in
	the reverse direction without tripping.
	The panel shall include a main discon-
	nect with short circuit protection and
	external operating handle, lockable in the
	off position for safety. The VFD system
	shall receive a speed reference signal
	from the Building Management System
	monitoring the tower fluid temperature.
	As an option to receiving the speed
	reference signal from a building manage-
	ment system, the drive must have the
	capability to receive a 4-20 ma tempera-
	ture signal from an RTD transmitter. The
	VFD shall have an internal PI regulator
	VFD shall have an internal PI regulator

➠

Basin Heater:

10.2

Add the following paragraph in the

Cold Water Basin section: Provide

a system of electric immersion heat-

ers and controls for each cell of the

the jobsite.

tower to prevent freezing of water in

the collection basin during periods of

shutdown. The system shall consist

nized” in paragraph 10.2 to “Series 300 SS”.

of one or more stainless steel elec-

tric immersion heaters installed in a

galvanized steel heat shield provided

1% level of winter temperature prevalent at site.

in the floor of the basin. A NEMA

Ask for Marley drawing 92-3627.

4 enclosure shall house a magnetic

contactor to energize heaters; a trans-

former to provide 24 volt control circuit

power; and a solid state circuit board

for temperature and low water cutoff.

A control probe shall be located in the

basin to monitor water level and tem-

perature. The system shall be capable

of maintaining 40°F water temperature

at an ambient air temperature of __ °F.

Wiring of the heaters and controls shall

be the responsibility of the purchaser.

Fan Motor Variable Speed Drive:

Marley All Weather ACH550 System

Mechanical Equipment section when

VFD is used with customers Building

Management System: A complete

UL listed Variable Speed Drive system

in a NEMA 1 indoor, NEMA 12 indoor

or NEMA 3R outdoor enclosure shall

be provided. The VFD shall use PWM

technology with IGBT switching and

integrated bypass design. VFD out put

switching shall not cause mechanical

issues with gearbox teeth or drive shafts.

The VFD shall catch a fan spinning in

the reverse direction without tripping.

The panel shall include a main discon-

nect with short circuit protection and

external operating handle, lockable in the

off position for safety. The VFD system

shall receive a speed reference signal

from the Building Management System

monitoring the tower fluid temperature.

As an option to receiving the speed

reference signal from a building manage-

ment system, the drive must have the

capability to receive a 4-20 ma tempera-

ture signal from an RTD transmitter. The

VFD shall have an internal PI regulator