SR504-EXP Switching Relay Instruction Manual

ManualsBrandsTaco ManualsHeating Supplies4 Zone Switching Relay w/ Priority

120 VAC INPUT

TO: "TT" ON BOILER

PRIMARY CIRCULATOR

(OPTIONAL)

TO: "TT" ON BOILER WITH

DHW "TT" INPUT

FOUR ZONE

EXPANDABLE

SWITCHING RELAY

POWER

CONTROLS

120 VAC CIRCULATORS

INPUT

120 VAC

ZONE 1

ZONE 2 ZONE 3 ZONE 4

ZONE1

ZONE2

ZONE3

THERMOSTATS

SR 504-EXP-4

FUSE

6 AMP

FUSE

6 AMP

FUSE

6 AMP

FUSE

6 AMP

FUSE

6 AMP

FUSE

6 AMP

NET

EXPANSIONMAIN PRIORITY

CRW

END SWITCH THERMOSTATS (24 VAC)

PRIORITY

N/C

PRIMARY

120 VAC

H H N H N H NH NH NH NH NH

SLAVE

PRIORITY ON

RESET

PRIMARY PUMP ON

POST PURGE ON

PRIORITY PROTECT ON

PUMP EXERCISE ON

30 SEC/2 WK

MASTER

OFF

NORMAL

LOW LIMIT (ZC) ON OFF

4 MIN/24 HOUR

ZONE4 ZONE4

PRIORITY

ACCESSORY

PORT

ZONE 2

POWER

ZONE 1

ZONE 3

ZONE 4

LED

INDICATORS

120 VAC INPUT

FOUR ZONE

EXPANDABLE

SWITCHING RELAY

POWER

CONTROLS

120 VAC CIRCULATORS

INPUT

120 VAC

ZONE 1

ZONE 2 ZONE 3 ZONE 4

ZONE1

ZONE2

ZONE3

THERMOSTATS

SR 504-EXP-4

FUSE

6 AMP

FUSE

6 AMP

FUSE

6 AMP

FUSE

6 AMP

FUSE

6 AMP

FUSE

6 AMP

NET

EXPANSIONMAIN PRIORITY

CRW

END SWITCH THERMOSTATS (24 VAC)

PRIORITY

N/C

PRIMARY

120 VAC

H H N H N H NH NH NH NH NH

SLAVE

PRIORITY ON

RESET

PRIMARY PUMP ON

POST PURGE ON

PRIORITY PROTECT ON

PUMP EXERCISE ON

30 SEC/2 WK

MASTER

OFF

NORMAL

LOW LIMIT (ZC) ON OFF

4 MIN/24 HOUR

ZONE4 ZONE4

PRIORITY

ACCESSORY

PORT

ZONE 2

POWER

ZONE 1

ZONE 3

ZONE 4

LED

INDICATORS

TO: "ZC" ON BOILER

TO: "ZR" ON BOILER

Priority Operation: When the priority dip switch is set to ON and the

priority zone is actuated, all other zones will stop operation until pri-

ority zone is satisfied. When not switched to priority, all zones will

operate independently.

Mode Operation: When the dip switch is set to NORMAL, the end

switch relay will be energized if any zone is in operation. When the switch

is set to RESET, the end switch relay will only be energized if the priority

zone is in operation, or through the operation of a plug-in reset control.

Primary Pump Operation: When the dip switch is set to OFF, the pri-

mary circulating pump output will energize when any zone calls for heat,

except the priority zone. When the dip switch is set to ON, the prima-

ry circulating pump output will energize when any zone calls for heat.

Post Purge Operation: When the dip switch is set to ON, the priori-

ty zone output will stay energized for 2 minutes after its thermostat or

aquastat is satisfied, but not operate the boiler.

Priority Protection Operation: When the dip switch is set to ON, and

if the priority zone calls continuously for more than one hour, power

is returned to all the other zones, allowing each zone to function inde-

pendently. Once the priority zone is satisfied, the control's auto-reset is

activated and the priority zone is again allowed to have priority for up

to one hour starting from when it calls next.

Pump Exercise Operation: When the dip switch is set to ON, the solid

state timer cycles all the circulating pumps that are attached to the

Expandable Switching Relay at the selected time interval. The time

interval can be set for the pumps to run for either 30 seconds every 2

weeks or for 4 minutes every 24 hours.

Low Limit (ZC) Operation: When the dip switch is set to ON and the

boiler drops below the set low limit (terminal ZC connected to boiler),

all zone circulating pumps will stop. When the boiler rises above the

set low limit, the zone circulating pumps are allowed to operate.

End Switches (Dry Contacts): The main end switch closes when any

zone thermostat calls for heat and the mode switch is set to NORMAL.

The main end switch also closes when the mode switch is set to RESET

and a PC Series boiler reset power control is calling for heat. The priori-

ty end switch closes only when the priority zone thermostat or aquastat

is calling for heat.

Expansion Connections: Set the expansion switch to MASTER on the

switching relay that has the designated priority zone or is utilizing the

PC Series plug-in option. Set all other daisy chained controls to SLAVE.

Using thermostat wire (18-22 gauge) connect between terminals A, B,

C on the master control to the corresponding A, B, C on the SLAVE

control(s). Controls may be daisy chained up to 20 zoning panels using

any combination of -EXP controls (120 zones if all are 6 zone panels).

Thermostat Input (24 vac):

R Hot side of transformer. Connect to R on thermostat.

W Switched R signal from thermostat. Connect to W on thermostat.

C Common side of transformer. Connect to COM on

thermostat (optional).

NET Network terminals 1 & 2 are tied together for wiring convenience

when using communicating style thermostats (optional).

120 VAC Connections (N is Neutral, H is Hot):

Power Input Connect 120 Volt AC power

Primary Primary Pump (optional)

Zone 1-3 Circulator Zones

Priority Zone 4 Priority Zone (if enabled) or Zone 4

N/C Zone 4 Normally closed terminals for the Priority Zone.

Will deactivate on a Priority Zone call.

Cold Start Boiler

Application

Tankless Coil Boiler

Application

(Alternative Wiring)

Instruction Sheet

SR504-EXP-4 Switching Relay

102-389

SUPERSEDES: New EFFECTIVE: May 1, 2010

Plant ID# 9300-2874

For Both Cold Start Boiler Application and Tankless Coil Boiler Application (Alternative Wiring)

For Cold Start Boiler Application

Operation: When any thermostat calls for heat, the appropriate circu-

lating pump is energized and the isolated end switch (X and X) will

start the boiler.

For Tankless Coil Boiler Application (Alternative Wiring)

Operation: When any thermostat calls for heat, the boiler will be enabled

and appropriate circulating pump is energized when the boiler tempera-

ture is above the set low limit and low limit (ZC) dip switch is set to on.

ZC and ZR Terminals: Connect terminal ZC to ZC terminal on the aqua-

stat control. Connect ZR to ZR terminal on the aquastat control. Confirm

polarity is consistent between boiler aquastat and switching relay.

WARNING: When using Alternative Wiring diagram, wiring instruc-

tions must be followed so power originates from the boiler aquastat.

Failure to follow these wiring instructions may result in a secondary

source of power being connected to the boiler that may activate it

under certain circumstances, causing injury or death.

Specifications:

PRODUCT NUMBER INPUT MAXIMUM TYPE 1 ENCLOSURE

NUMBER OF ZONES VOLTAGE COMBINED LOAD WIDTH HEIGHT DEPTH

SR504-EXP-4 4 with Priority 120/60/1 VAC 20 amps 10

/4"7" 2

/4"

All circulator relay connections, including ZC/ZR, are rated

/3 hp (6 FLA, 36 LRA) at 120 VAC.

End switch connections are rated 24 VAC, 1 amp.

All thermostat connections supply a 24 VAC class 2 output.

For more wiring diagrams, visit www.taco-hvac.com.

WARNING: Wiring connections must be made in accordance with all

applicable electrical codes. Use copper wire only. 120 VAC wiring must have

a minimum temperature rating of 75°C. Failure to follow this instruction

can result in personal injury or death and/or property damage. 12-18 gauge

wire recommended for 120 VAC connections, 14-22 gauge wire for ther-

mostat connections, and 14-22 gauge wire for 24 VAC source connections.

Summary of content (2 pages)

PAGE 1
Instruction Sheet 102-389 SR504-EXP-4 Switching Relay SUPERSEDES: New Plant ID# 9300-2874 Cold Start Boiler Application EFFECTIVE: May 1, 2010 TO: "TT" ON BOILER WITH DHW "TT" INPUT THERMOSTATS TO: "TT" ON BOILER SLAVE POWER CONTROLS MASTER POWER CONTROLS OFF PRIORITY ON X X X X NORMAL RESET A B C R W C R W C R W C R W C 1 2 PRIMARY PUMP ON OFF MAIN PRIORITY EXPANSION POST PURGE ON PRIORITY PROTECT ON PUMP EXERCISE ON OFF OFF OFF END SWITCH ZONE 1 ZONE 2 ZONE 3 THERMOSTATS (24 VAC)
PAGE 2
Dip Switch Settings: SLAVE ZONE PRIORITY ON RESET PRIMARY PUMP FUNCTION ON POST PURGE ON PRIORITY PROTECTION ON PUMP EXERCISE ON 30 SEC/2 WK LOW LIMIT (ZC) ON This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.